NORTHWESTERN CORPORATION has sponsored the creation of one or more 401k plans.
Submission information for form 5500 for 401k plan NORTHWESTERN ENERGY PENSION PLAN
| Measure | Date | Value |
|---|
| 2022: NORTHWESTERN ENERGY PENSION PLAN 2022 401k membership |
|---|
| Market value of plan assets | 2022-12-31 | 544,479,128 |
| Acturial value of plan assets | 2022-12-31 | 516,621,137 |
| Funding target for retired participants and beneficiaries receiving payment | 2022-12-31 | 249,683,304 |
| Number of terminated vested participants | 2022-12-31 | 305 |
| Fundng target for terminated vested participants | 2022-12-31 | 54,290,429 |
| Active participant vested funding target | 2022-12-31 | 155,588,309 |
| Number of active participants | 2022-12-31 | 451 |
| Total funding liabilities for active participants | 2022-12-31 | 157,617,953 |
| Total participant count | 2022-12-31 | 1,367 |
| Total funding target for all participants | 2022-12-31 | 461,591,686 |
| Balance at beginning of prior year after applicable adjustments | 2022-12-31 | 0 |
| Prefunding balance at beginning of prior year after applicable adjustments | 2022-12-31 | 0 |
| Carryover balanced portion elected for use to offset prior years funding requirement | 2022-12-31 | 0 |
| Prefunding balanced used to offset prior years funding requirement | 2022-12-31 | 0 |
| Amount remaining of carryover balance | 2022-12-31 | 0 |
| Amount remaining of prefunding balance | 2022-12-31 | 0 |
| Present value of excess contributions | 2022-12-31 | 12,568,644 |
| Total available prior years excess cotributions available at beginning of current plan year to add to prefunding balance | 2022-12-31 | 13,272,488 |
| Total available prior years excess cotributions added at beginning of current plan year to add to prefunding balance | 2022-12-31 | 0 |
| Reductions in caryover balances due to elections or deemed elections | 2022-12-31 | 0 |
| Reductions in prefunding balances due to elections or deemed elections | 2022-12-31 | 0 |
| Balance of carryovers at beginning of current year | 2022-12-31 | 0 |
| Balance of prefunding at beginning of current year | 2022-12-31 | 0 |
| Total employer contributions | 2022-12-31 | 7,000,000 |
| Total employee contributions | 2022-12-31 | 0 |
| Contributions allocated toward unpaid minimum require contributions from prior years | 2022-12-31 | 0 |
| Contributions made to avoid restrictions adjusted to valuation date | 2022-12-31 | 0 |
| Contributions allocated toward minimum required contributions for current year adjusted to valuation date | 2022-12-31 | 6,425,204 |
| Unpaid minimum required contributions for all prior years | 2022-12-31 | 0 |
| iDiscounted employer contributions allocated toward unpaid minimum required contributions from prior years | 2022-12-31 | 0 |
| Remaining amount of unpaid minimum required contributions | 2022-12-31 | 0 |
| Minimum required contributions for current year target normal cost | 2022-12-31 | 5,691,838 |
| Net shortfall amortization installment of oustanding balance | 2022-12-31 | 0 |
| Waiver amortization installment | 2022-12-31 | 0 |
| Total funding amount beforereflecting carryover/prefunding balances | 2022-12-31 | 0 |
| Carryover balance elected to use to offset funding requirement | 2022-12-31 | 0 |
| Prefunding balance elected to use to offset funding requirement | 2022-12-31 | 0 |
| Additional cash requirement | 2022-12-31 | 0 |
| Contributions allocatedtoward minimum required contributions for current year | 2022-12-31 | 6,425,204 |
| Unpaid minimum required contributions for current year | 2022-12-31 | 0 |
| Unpaid minimum required contributions for all years | 2022-12-31 | 0 |
| Total participants, beginning-of-year | 2022-01-01 | 1,341 |
| Total number of active participants reported on line 7a of the Form 5500 | 2022-01-01 | 391 |
| Number of retired or separated participants receiving benefits | 2022-01-01 | 637 |
| Number of other retired or separated participants entitled to future benefits | 2022-01-01 | 256 |
| Total of all active and inactive participants | 2022-01-01 | 1,284 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2022-01-01 | 43 |
| Total participants | 2022-01-01 | 1,327 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2022-01-01 | 0 |
| 2021: NORTHWESTERN ENERGY PENSION PLAN 2021 401k membership |
|---|
| Market value of plan assets | 2021-12-31 | 620,894,069 |
| Acturial value of plan assets | 2021-12-31 | 558,804,663 |
| Funding target for retired participants and beneficiaries receiving payment | 2021-12-31 | 301,877,121 |
| Number of terminated vested participants | 2021-12-31 | 301 |
| Fundng target for terminated vested participants | 2021-12-31 | 43,940,085 |
| Active participant vested funding target | 2021-12-31 | 175,268,980 |
| Number of active participants | 2021-12-31 | 528 |
| Total funding liabilities for active participants | 2021-12-31 | 177,457,777 |
| Total participant count | 2021-12-31 | 2,497 |
| Total funding target for all participants | 2021-12-31 | 523,274,983 |
| Balance at beginning of prior year after applicable adjustments | 2021-12-31 | 0 |
| Prefunding balance at beginning of prior year after applicable adjustments | 2021-12-31 | 0 |
| Carryover balanced portion elected for use to offset prior years funding requirement | 2021-12-31 | 0 |
| Prefunding balanced used to offset prior years funding requirement | 2021-12-31 | 0 |
| Amount remaining of carryover balance | 2021-12-31 | 0 |
| Amount remaining of prefunding balance | 2021-12-31 | 0 |
| Present value of excess contributions | 2021-12-31 | 0 |
| Total available prior years excess cotributions available at beginning of current plan year to add to prefunding balance | 2021-12-31 | 0 |
| Balance of carryovers at beginning of current year | 2021-12-31 | 0 |
| Balance of prefunding at beginning of current year | 2021-12-31 | 0 |
| Total employer contributions | 2021-12-31 | 13,312,351 |
| Total employee contributions | 2021-12-31 | 0 |
| Contributions allocated toward minimum required contributions for current year adjusted to valuation date | 2021-12-31 | 12,568,645 |
| Liquidity shortfalls end of Q1 | 2021-12-31 | 0 |
| Liquidity shortfalls end of Q2 | 2021-12-31 | 0 |
| Liquidity shortfalls end of Q3 | 2021-12-31 | 0 |
| Liquidity shortfalls end of Q4 | 2021-12-31 | 0 |
| Remaining amount of unpaid minimum required contributions | 2021-12-31 | 0 |
| Minimum required contributions for current year target normal cost | 2021-12-31 | 6,990,069 |
| Total funding amount beforereflecting carryover/prefunding balances | 2021-12-31 | 0 |
| Additional cash requirement | 2021-12-31 | 0 |
| Contributions allocatedtoward minimum required contributions for current year | 2021-12-31 | 12,568,645 |
| Unpaid minimum required contributions for current year | 2021-12-31 | 0 |
| Unpaid minimum required contributions for all years | 2021-12-31 | 0 |
| Total participants, beginning-of-year | 2021-01-01 | 2,423 |
| Total number of active participants reported on line 7a of the Form 5500 | 2021-01-01 | 451 |
| Number of retired or separated participants receiving benefits | 2021-01-01 | 578 |
| Number of other retired or separated participants entitled to future benefits | 2021-01-01 | 272 |
| Total of all active and inactive participants | 2021-01-01 | 1,301 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2021-01-01 | 41 |
| Total participants | 2021-01-01 | 1,342 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2021-01-01 | 0 |
| 2020: NORTHWESTERN ENERGY PENSION PLAN 2020 401k membership |
|---|
| Market value of plan assets | 2020-12-31 | 548,345,232 |
| Acturial value of plan assets | 2020-12-31 | 520,094,796 |
| Funding target for retired participants and beneficiaries receiving payment | 2020-12-31 | 289,684,122 |
| Number of terminated vested participants | 2020-12-31 | 315 |
| Fundng target for terminated vested participants | 2020-12-31 | 46,668,485 |
| Active participant vested funding target | 2020-12-31 | 183,237,854 |
| Number of active participants | 2020-12-31 | 570 |
| Total funding liabilities for active participants | 2020-12-31 | 185,516,276 |
| Total participant count | 2020-12-31 | 2,539 |
| Total funding target for all participants | 2020-12-31 | 521,868,883 |
| Balance at beginning of prior year after applicable adjustments | 2020-12-31 | 0 |
| Prefunding balance at beginning of prior year after applicable adjustments | 2020-12-31 | 0 |
| Prefunding balanced used to offset prior years funding requirement | 2020-12-31 | 0 |
| Amount remaining of carryover balance | 2020-12-31 | 0 |
| Amount remaining of prefunding balance | 2020-12-31 | 0 |
| Present value of excess contributions | 2020-12-31 | 6,970 |
| Total available prior years excess cotributions available at beginning of current plan year to add to prefunding balance | 2020-12-31 | 7,357 |
| Balance of carryovers at beginning of current year | 2020-12-31 | 0 |
| Balance of prefunding at beginning of current year | 2020-12-31 | 0 |
| Total employer contributions | 2020-12-31 | 9,902,585 |
| Total employee contributions | 2020-12-31 | 0 |
| Contributions allocated toward unpaid minimum require contributions from prior years | 2020-12-31 | 0 |
| Contributions made to avoid restrictions adjusted to valuation date | 2020-12-31 | 0 |
| Contributions allocated toward minimum required contributions for current year adjusted to valuation date | 2020-12-31 | 9,553,475 |
| Liquidity shortfalls end of Q1 | 2020-12-31 | 0 |
| Liquidity shortfalls end of Q2 | 2020-12-31 | 0 |
| Liquidity shortfalls end of Q3 | 2020-12-31 | 0 |
| Liquidity shortfalls end of Q4 | 2020-12-31 | 0 |
| Unpaid minimum required contributions for all prior years | 2020-12-31 | 0 |
| iDiscounted employer contributions allocated toward unpaid minimum required contributions from prior years | 2020-12-31 | 0 |
| Remaining amount of unpaid minimum required contributions | 2020-12-31 | 0 |
| Minimum required contributions for current year target normal cost | 2020-12-31 | 8,305,125 |
| Net shortfall amortization installment of oustanding balance | 2020-12-31 | 1,774,087 |
| Total funding amount beforereflecting carryover/prefunding balances | 2020-12-31 | 9,553,475 |
| Carryover balance elected to use to offset funding requirement | 2020-12-31 | 0 |
| Prefunding balance elected to use to offset funding requirement | 2020-12-31 | 0 |
| Additional cash requirement | 2020-12-31 | 9,553,475 |
| Contributions allocatedtoward minimum required contributions for current year | 2020-12-31 | 9,553,475 |
| Unpaid minimum required contributions for current year | 2020-12-31 | 0 |
| Unpaid minimum required contributions for all years | 2020-12-31 | 0 |
| Total participants, beginning-of-year | 2020-01-01 | 2,472 |
| Total number of active participants reported on line 7a of the Form 5500 | 2020-01-01 | 528 |
| Number of retired or separated participants receiving benefits | 2020-01-01 | 1,395 |
| Number of other retired or separated participants entitled to future benefits | 2020-01-01 | 275 |
| Total of all active and inactive participants | 2020-01-01 | 2,198 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2020-01-01 | 225 |
| Total participants | 2020-01-01 | 2,423 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2020-01-01 | 0 |
| 2019: NORTHWESTERN ENERGY PENSION PLAN 2019 401k membership |
|---|
| Market value of plan assets | 2019-12-31 | 466,578,463 |
| Acturial value of plan assets | 2019-12-31 | 491,653,221 |
| Funding target for retired participants and beneficiaries receiving payment | 2019-12-31 | 275,264,439 |
| Number of terminated vested participants | 2019-12-31 | 308 |
| Fundng target for terminated vested participants | 2019-12-31 | 37,262,715 |
| Active participant vested funding target | 2019-12-31 | 193,763,097 |
| Number of active participants | 2019-12-31 | 633 |
| Total funding liabilities for active participants | 2019-12-31 | 196,223,482 |
| Total participant count | 2019-12-31 | 2,588 |
| Total funding target for all participants | 2019-12-31 | 508,750,636 |
| Balance at beginning of prior year after applicable adjustments | 2019-12-31 | 0 |
| Prefunding balance at beginning of prior year after applicable adjustments | 2019-12-31 | 10,513,324 |
| Carryover balanced portion elected for use to offset prior years funding requirement | 2019-12-31 | 0 |
| Prefunding balanced used to offset prior years funding requirement | 2019-12-31 | 10,513,324 |
| Amount remaining of carryover balance | 2019-12-31 | 0 |
| Amount remaining of prefunding balance | 2019-12-31 | 0 |
| Present value of excess contributions | 2019-12-31 | 3,394 |
| Total available prior years excess cotributions available at beginning of current plan year to add to prefunding balance | 2019-12-31 | 3,158 |
| Reductions in prefunding balances due to elections or deemed elections | 2019-12-31 | 0 |
| Balance of carryovers at beginning of current year | 2019-12-31 | 0 |
| Balance of prefunding at beginning of current year | 2019-12-31 | 0 |
| Total employer contributions | 2019-12-31 | 11,901,327 |
| Total employee contributions | 2019-12-31 | 0 |
| Contributions allocated toward unpaid minimum require contributions from prior years | 2019-12-31 | 0 |
| Contributions made to avoid restrictions adjusted to valuation date | 2019-12-31 | 0 |
| Contributions allocated toward minimum required contributions for current year adjusted to valuation date | 2019-12-31 | 11,436,625 |
| Liquidity shortfalls end of Q1 | 2019-12-31 | 0 |
| Liquidity shortfalls end of Q2 | 2019-12-31 | 0 |
| Liquidity shortfalls end of Q3 | 2019-12-31 | 0 |
| Liquidity shortfalls end of Q4 | 2019-12-31 | 0 |
| Unpaid minimum required contributions for all prior years | 2019-12-31 | 0 |
| iDiscounted employer contributions allocated toward unpaid minimum required contributions from prior years | 2019-12-31 | 0 |
| Remaining amount of unpaid minimum required contributions | 2019-12-31 | 0 |
| Minimum required contributions for current year target normal cost | 2019-12-31 | 8,122,935 |
| Net shortfall amortization installment of oustanding balance | 2019-12-31 | 17,097,415 |
| Total funding amount beforereflecting carryover/prefunding balances | 2019-12-31 | 11,429,873 |
| Prefunding balance elected to use to offset funding requirement | 2019-12-31 | 0 |
| Additional cash requirement | 2019-12-31 | 11,429,873 |
| Contributions allocatedtoward minimum required contributions for current year | 2019-12-31 | 11,436,625 |
| Unpaid minimum required contributions for current year | 2019-12-31 | 0 |
| Unpaid minimum required contributions for all years | 2019-12-31 | 0 |
| Total participants, beginning-of-year | 2019-01-01 | 2,516 |
| Total number of active participants reported on line 7a of the Form 5500 | 2019-01-01 | 570 |
| Number of retired or separated participants receiving benefits | 2019-01-01 | 1,391 |
| Number of other retired or separated participants entitled to future benefits | 2019-01-01 | 286 |
| Total of all active and inactive participants | 2019-01-01 | 2,247 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2019-01-01 | 225 |
| Total participants | 2019-01-01 | 2,472 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2019-01-01 | 0 |
| 2018: NORTHWESTERN ENERGY PENSION PLAN 2018 401k membership |
|---|
| Market value of plan assets | 2018-12-31 | 530,276,267 |
| Acturial value of plan assets | 2018-12-31 | 492,442,125 |
| Funding target for retired participants and beneficiaries receiving payment | 2018-12-31 | 260,686,609 |
| Number of terminated vested participants | 2018-12-31 | 313 |
| Fundng target for terminated vested participants | 2018-12-31 | 34,926,034 |
| Active participant vested funding target | 2018-12-31 | 195,685,175 |
| Number of active participants | 2018-12-31 | 686 |
| Total funding liabilities for active participants | 2018-12-31 | 198,116,103 |
| Total participant count | 2018-12-31 | 2,628 |
| Total funding target for all participants | 2018-12-31 | 493,728,746 |
| Balance at beginning of prior year after applicable adjustments | 2018-12-31 | 0 |
| Prefunding balance at beginning of prior year after applicable adjustments | 2018-12-31 | 27,543,256 |
| Prefunding balanced used to offset prior years funding requirement | 2018-12-31 | 8,663,904 |
| Amount remaining of carryover balance | 2018-12-31 | 0 |
| Amount remaining of prefunding balance | 2018-12-31 | 18,879,352 |
| Present value of excess contributions | 2018-12-31 | 7,769,347 |
| Total available prior years excess cotributions available at beginning of current plan year to add to prefunding balance | 2018-12-31 | 9,059,059 |
| Reductions in prefunding balances due to elections or deemed elections | 2018-12-31 | 11,500,000 |
| Balance of carryovers at beginning of current year | 2018-12-31 | 0 |
| Balance of prefunding at beginning of current year | 2018-12-31 | 10,513,324 |
| Total employer contributions | 2018-12-31 | 85,000 |
| Total employee contributions | 2018-12-31 | 0 |
| Contributions allocated toward unpaid minimum require contributions from prior years | 2018-12-31 | 0 |
| Contributions made to avoid restrictions adjusted to valuation date | 2018-12-31 | 0 |
| Contributions allocated toward minimum required contributions for current year adjusted to valuation date | 2018-12-31 | 79,127 |
| Liquidity shortfalls end of Q1 | 2018-12-31 | 0 |
| Liquidity shortfalls end of Q2 | 2018-12-31 | 0 |
| Liquidity shortfalls end of Q3 | 2018-12-31 | 0 |
| Liquidity shortfalls end of Q4 | 2018-12-31 | 0 |
| Unpaid minimum required contributions for all prior years | 2018-12-31 | 0 |
| iDiscounted employer contributions allocated toward unpaid minimum required contributions from prior years | 2018-12-31 | 0 |
| Remaining amount of unpaid minimum required contributions | 2018-12-31 | 0 |
| Minimum required contributions for current year target normal cost | 2018-12-31 | 8,414,126 |
| Net shortfall amortization installment of oustanding balance | 2018-12-31 | 11,799,945 |
| Total funding amount beforereflecting carryover/prefunding balances | 2018-12-31 | 10,589,057 |
| Prefunding balance elected to use to offset funding requirement | 2018-12-31 | 10,513,324 |
| Additional cash requirement | 2018-12-31 | 75,733 |
| Contributions allocatedtoward minimum required contributions for current year | 2018-12-31 | 79,127 |
| Unpaid minimum required contributions for current year | 2018-12-31 | 0 |
| Unpaid minimum required contributions for all years | 2018-12-31 | 0 |
| Total participants, beginning-of-year | 2018-01-01 | 2,558 |
| Total number of active participants reported on line 7a of the Form 5500 | 2018-01-01 | 633 |
| Number of retired or separated participants receiving benefits | 2018-01-01 | 1,388 |
| Number of other retired or separated participants entitled to future benefits | 2018-01-01 | 278 |
| Total of all active and inactive participants | 2018-01-01 | 2,299 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2018-01-01 | 217 |
| Total participants | 2018-01-01 | 2,516 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2018-01-01 | 0 |
| 2017: NORTHWESTERN ENERGY PENSION PLAN 2017 401k membership |
|---|
| Market value of plan assets | 2017-12-31 | 471,213,734 |
| Acturial value of plan assets | 2017-12-31 | 476,773,932 |
| Funding target for retired participants and beneficiaries receiving payment | 2017-12-31 | 228,906,888 |
| Number of terminated vested participants | 2017-12-31 | 325 |
| Fundng target for terminated vested participants | 2017-12-31 | 28,617,928 |
| Active participant vested funding target | 2017-12-31 | 196,005,124 |
| Number of active participants | 2017-12-31 | 749 |
| Total funding liabilities for active participants | 2017-12-31 | 198,280,738 |
| Total participant count | 2017-12-31 | 2,660 |
| Total funding target for all participants | 2017-12-31 | 455,805,554 |
| Balance at beginning of prior year after applicable adjustments | 2017-12-31 | 0 |
| Prefunding balance at beginning of prior year after applicable adjustments | 2017-12-31 | 38,762,955 |
| Prefunding balanced used to offset prior years funding requirement | 2017-12-31 | 2,377,920 |
| Amount remaining of carryover balance | 2017-12-31 | 0 |
| Amount remaining of prefunding balance | 2017-12-31 | 36,385,035 |
| Present value of excess contributions | 2017-12-31 | 0 |
| Total available prior years excess cotributions available at beginning of current plan year to add to prefunding balance | 2017-12-31 | 0 |
| Reductions in prefunding balances due to elections or deemed elections | 2017-12-31 | 12,000,000 |
| Balance of carryovers at beginning of current year | 2017-12-31 | 0 |
| Balance of prefunding at beginning of current year | 2017-12-31 | 27,543,256 |
| Total employer contributions | 2017-12-31 | 9,500,000 |
| Total employee contributions | 2017-12-31 | 0 |
| Contributions allocated toward unpaid minimum require contributions from prior years | 2017-12-31 | 0 |
| Contributions made to avoid restrictions adjusted to valuation date | 2017-12-31 | 0 |
| Contributions allocated toward minimum required contributions for current year adjusted to valuation date | 2017-12-31 | 8,732,001 |
| Liquidity shortfalls end of Q1 | 2017-12-31 | 0 |
| Liquidity shortfalls end of Q2 | 2017-12-31 | 0 |
| Liquidity shortfalls end of Q3 | 2017-12-31 | 0 |
| Liquidity shortfalls end of Q4 | 2017-12-31 | 0 |
| Unpaid minimum required contributions for all prior years | 2017-12-31 | 0 |
| iDiscounted employer contributions allocated toward unpaid minimum required contributions from prior years | 2017-12-31 | 0 |
| Remaining amount of unpaid minimum required contributions | 2017-12-31 | 0 |
| Minimum required contributions for current year target normal cost | 2017-12-31 | 8,444,358 |
| Net shortfall amortization installment of oustanding balance | 2017-12-31 | 6,574,878 |
| Total funding amount beforereflecting carryover/prefunding balances | 2017-12-31 | 9,626,558 |
| Prefunding balance elected to use to offset funding requirement | 2017-12-31 | 8,663,904 |
| Additional cash requirement | 2017-12-31 | 962,654 |
| Contributions allocatedtoward minimum required contributions for current year | 2017-12-31 | 8,732,001 |
| Unpaid minimum required contributions for current year | 2017-12-31 | 0 |
| Unpaid minimum required contributions for all years | 2017-12-31 | 0 |
| Total participants, beginning-of-year | 2017-01-01 | 2,593 |
| Total number of active participants reported on line 7a of the Form 5500 | 2017-01-01 | 686 |
| Number of retired or separated participants receiving benefits | 2017-01-01 | 1,369 |
| Number of other retired or separated participants entitled to future benefits | 2017-01-01 | 280 |
| Total of all active and inactive participants | 2017-01-01 | 2,335 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2017-01-01 | 223 |
| Total participants | 2017-01-01 | 2,558 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2017-01-01 | 0 |
| 2016: NORTHWESTERN ENERGY PENSION PLAN 2016 401k membership |
|---|
| Market value of plan assets | 2016-12-31 | 451,317,469 |
| Acturial value of plan assets | 2016-12-31 | 471,249,555 |
| Funding target for retired participants and beneficiaries receiving payment | 2016-12-31 | 208,658,971 |
| Number of terminated vested participants | 2016-12-31 | 348 |
| Fundng target for terminated vested participants | 2016-12-31 | 26,378,124 |
| Active participant vested funding target | 2016-12-31 | 200,504,929 |
| Number of active participants | 2016-12-31 | 824 |
| Total funding liabilities for active participants | 2016-12-31 | 202,725,559 |
| Total participant count | 2016-12-31 | 2,709 |
| Total funding target for all participants | 2016-12-31 | 437,762,654 |
| Balance at beginning of prior year after applicable adjustments | 2016-12-31 | 0 |
| Prefunding balance at beginning of prior year after applicable adjustments | 2016-12-31 | 39,793,609 |
| Carryover balanced portion elected for use to offset prior years funding requirement | 2016-12-31 | 0 |
| Prefunding balanced used to offset prior years funding requirement | 2016-12-31 | 0 |
| Amount remaining of carryover balance | 2016-12-31 | 0 |
| Amount remaining of prefunding balance | 2016-12-31 | 39,793,609 |
| Present value of excess contributions | 2016-12-31 | 6,552,761 |
| Total available prior years excess cotributions available at beginning of current plan year to add to prefunding balance | 2016-12-31 | 6,965,585 |
| Balance of carryovers at beginning of current year | 2016-12-31 | 0 |
| Balance of prefunding at beginning of current year | 2016-12-31 | 38,762,955 |
| Total employer contributions | 2016-12-31 | 9,000,000 |
| Total employee contributions | 2016-12-31 | 0 |
| Contributions allocated toward unpaid minimum require contributions from prior years | 2016-12-31 | 0 |
| Contributions made to avoid restrictions adjusted to valuation date | 2016-12-31 | 0 |
| Contributions allocated toward minimum required contributions for current year adjusted to valuation date | 2016-12-31 | 8,281,216 |
| Unpaid minimum required contributions for all prior years | 2016-12-31 | 0 |
| iDiscounted employer contributions allocated toward unpaid minimum required contributions from prior years | 2016-12-31 | 0 |
| Remaining amount of unpaid minimum required contributions | 2016-12-31 | 0 |
| Minimum required contributions for current year target normal cost | 2016-12-31 | 9,787,408 |
| Net shortfall amortization installment of oustanding balance | 2016-12-31 | 5,276,054 |
| Total funding amount beforereflecting carryover/prefunding balances | 2016-12-31 | 10,659,136 |
| Prefunding balance elected to use to offset funding requirement | 2016-12-31 | 2,377,920 |
| Additional cash requirement | 2016-12-31 | 8,281,216 |
| Contributions allocatedtoward minimum required contributions for current year | 2016-12-31 | 8,281,216 |
| Unpaid minimum required contributions for current year | 2016-12-31 | 0 |
| Unpaid minimum required contributions for all years | 2016-12-31 | 0 |
| Total participants, beginning-of-year | 2016-01-01 | 2,637 |
| Total number of active participants reported on line 7a of the Form 5500 | 2016-01-01 | 749 |
| Number of retired or separated participants receiving benefits | 2016-01-01 | 1,339 |
| Number of other retired or separated participants entitled to future benefits | 2016-01-01 | 290 |
| Total of all active and inactive participants | 2016-01-01 | 2,378 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2016-01-01 | 215 |
| Total participants | 2016-01-01 | 2,593 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2016-01-01 | 0 |
| 2015: NORTHWESTERN ENERGY PENSION PLAN 2015 401k membership |
|---|
| Total participants, beginning-of-year | 2015-01-01 | 3,004 |
| Total number of active participants reported on line 7a of the Form 5500 | 2015-01-01 | 824 |
| Number of retired or separated participants receiving benefits | 2015-01-01 | 1,297 |
| Number of other retired or separated participants entitled to future benefits | 2015-01-01 | 298 |
| Total of all active and inactive participants | 2015-01-01 | 2,419 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2015-01-01 | 218 |
| Total participants | 2015-01-01 | 2,637 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2015-01-01 | 0 |
| 2014: NORTHWESTERN ENERGY PENSION PLAN 2014 401k membership |
|---|
| Total participants, beginning-of-year | 2014-01-01 | 2,967 |
| Total number of active participants reported on line 7a of the Form 5500 | 2014-01-01 | 880 |
| Number of retired or separated participants receiving benefits | 2014-01-01 | 1,268 |
| Number of other retired or separated participants entitled to future benefits | 2014-01-01 | 643 |
| Total of all active and inactive participants | 2014-01-01 | 2,791 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2014-01-01 | 213 |
| Total participants | 2014-01-01 | 3,004 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2014-01-01 | 0 |
| 2013: NORTHWESTERN ENERGY PENSION PLAN 2013 401k membership |
|---|
| Total participants, beginning-of-year | 2013-01-01 | 2,993 |
| Total number of active participants reported on line 7a of the Form 5500 | 2013-01-01 | 861 |
| Number of retired or separated participants receiving benefits | 2013-01-01 | 1,286 |
| Number of other retired or separated participants entitled to future benefits | 2013-01-01 | 606 |
| Total of all active and inactive participants | 2013-01-01 | 2,753 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2013-01-01 | 214 |
| Total participants | 2013-01-01 | 2,967 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2013-01-01 | 0 |
| 2012: NORTHWESTERN ENERGY PENSION PLAN 2012 401k membership |
|---|
| Total participants, beginning-of-year | 2012-01-01 | 3,020 |
| Total number of active participants reported on line 7a of the Form 5500 | 2012-01-01 | 901 |
| Number of retired or separated participants receiving benefits | 2012-01-01 | 1,184 |
| Number of other retired or separated participants entitled to future benefits | 2012-01-01 | 697 |
| Total of all active and inactive participants | 2012-01-01 | 2,782 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2012-01-01 | 211 |
| Total participants | 2012-01-01 | 2,993 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2012-01-01 | 0 |
| 2011: NORTHWESTERN ENERGY PENSION PLAN 2011 401k membership |
|---|
| Total participants, beginning-of-year | 2011-01-01 | 3,071 |
| Total number of active participants reported on line 7a of the Form 5500 | 2011-01-01 | 947 |
| Number of retired or separated participants receiving benefits | 2011-01-01 | 1,158 |
| Number of other retired or separated participants entitled to future benefits | 2011-01-01 | 715 |
| Total of all active and inactive participants | 2011-01-01 | 2,820 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2011-01-01 | 200 |
| Total participants | 2011-01-01 | 3,020 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2011-01-01 | 0 |
| 2009: NORTHWESTERN ENERGY PENSION PLAN 2009 401k membership |
|---|
| Total participants, beginning-of-year | 2009-01-01 | 3,176 |
| Total number of active participants reported on line 7a of the Form 5500 | 2009-01-01 | 1,032 |
| Number of retired or separated participants receiving benefits | 2009-01-01 | 1,122 |
| Number of other retired or separated participants entitled to future benefits | 2009-01-01 | 798 |
| Total of all active and inactive participants | 2009-01-01 | 2,952 |
| Number of deceased participants whose beneficiaries are receiving or are entitled to receive benefits | 2009-01-01 | 180 |
| Total participants | 2009-01-01 | 3,132 |
| Participants that terminated employment during the plan year with accrued benefits that were less than 100% vested | 2009-01-01 | 13 |
| Measure | Date | Value |
|---|
| 2022 : NORTHWESTERN ENERGY PENSION PLAN 2022 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2022-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2022-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2022-12-31 | $205,831 |
| Total income from all sources (including contributions) | 2022-12-31 | $-124,278,261 |
| Total loss/gain on sale of assets | 2022-12-31 | $0 |
| Total of all expenses incurred | 2022-12-31 | $25,099,482 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2022-12-31 | $24,179,556 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2022-12-31 | $7,000,000 |
| Value of total assets at end of year | 2022-12-31 | $395,349,017 |
| Value of total assets at beginning of year | 2022-12-31 | $544,932,591 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2022-12-31 | $919,926 |
| Total interest from all sources | 2022-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2022-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2022-12-31 | No |
| Was this plan covered by a fidelity bond | 2022-12-31 | Yes |
| Value of fidelity bond cover | 2022-12-31 | $10,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2022-12-31 | No |
| Value of other receiveables (less allowance for doubtful accounts) at end of year | 2022-12-31 | $0 |
| Value of other receiveables (less allowance for doubtful accounts) at beginning of year | 2022-12-31 | $639,600 |
| Administrative expenses (other) incurred | 2022-12-31 | $919,926 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2022-12-31 | No |
| Value of net income/loss | 2022-12-31 | $-149,377,743 |
| Value of net assets at end of year (total assets less liabilities) | 2022-12-31 | $395,349,017 |
| Value of net assets at beginning of year (total assets less liabilities) | 2022-12-31 | $544,726,760 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2022-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2022-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2022-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2022-12-31 | $388,349,017 |
| Value of interest in master investment trust accounts at beginning of year | 2022-12-31 | $537,292,991 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2022-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2022-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2022-12-31 | No |
| Contributions received in cash from employer | 2022-12-31 | $7,000,000 |
| Employer contributions (assets) at end of year | 2022-12-31 | $7,000,000 |
| Employer contributions (assets) at beginning of year | 2022-12-31 | $7,000,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2022-12-31 | $24,179,556 |
| Liabilities. Value of benefit claims payable at end of year | 2022-12-31 | $0 |
| Liabilities. Value of benefit claims payable at beginning of year | 2022-12-31 | $205,831 |
| Did the plan have assets held for investment | 2022-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2022-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2022-12-31 | No |
| Opinion of an independent qualified public accountant for this plan | 2022-12-31 | Unqualified |
| Accountancy firm name | 2022-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2022-12-31 | 450250958 |
| 2021 : NORTHWESTERN ENERGY PENSION PLAN 2021 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2021-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2021-12-31 | $205,831 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2021-12-31 | $0 |
| Total income from all sources (including contributions) | 2021-12-31 | $48,838,814 |
| Total loss/gain on sale of assets | 2021-12-31 | $0 |
| Total of all expenses incurred | 2021-12-31 | $125,050,262 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2021-12-31 | $123,432,366 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2021-12-31 | $13,312,351 |
| Value of total assets at end of year | 2021-12-31 | $544,932,591 |
| Value of total assets at beginning of year | 2021-12-31 | $620,938,208 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2021-12-31 | $1,617,896 |
| Total interest from all sources | 2021-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2021-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2021-12-31 | No |
| Was this plan covered by a fidelity bond | 2021-12-31 | Yes |
| Value of fidelity bond cover | 2021-12-31 | $10,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2021-12-31 | No |
| Expenses. Other payments made (not to insurance carriers or or participants/beneficiaries) | 2021-12-31 | $92,848,067 |
| Value of other receiveables (less allowance for doubtful accounts) at end of year | 2021-12-31 | $639,600 |
| Administrative expenses (other) incurred | 2021-12-31 | $1,617,896 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2021-12-31 | No |
| Value of net income/loss | 2021-12-31 | $-76,211,448 |
| Value of net assets at end of year (total assets less liabilities) | 2021-12-31 | $544,726,760 |
| Value of net assets at beginning of year (total assets less liabilities) | 2021-12-31 | $620,938,208 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2021-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2021-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2021-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2021-12-31 | $537,292,991 |
| Value of interest in master investment trust accounts at beginning of year | 2021-12-31 | $618,250,559 |
| Net investment gain or loss from common/collective trusts | 2021-12-31 | $35,526,463 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2021-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2021-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2021-12-31 | No |
| Contributions received in cash from employer | 2021-12-31 | $13,312,351 |
| Employer contributions (assets) at end of year | 2021-12-31 | $7,000,000 |
| Employer contributions (assets) at beginning of year | 2021-12-31 | $2,687,649 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2021-12-31 | $30,584,299 |
| Liabilities. Value of benefit claims payable at end of year | 2021-12-31 | $205,831 |
| Did the plan have assets held for investment | 2021-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2021-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2021-12-31 | No |
| Opinion of an independent qualified public accountant for this plan | 2021-12-31 | Unqualified |
| Accountancy firm name | 2021-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2021-12-31 | 450250958 |
| 2020 : NORTHWESTERN ENERGY PENSION PLAN 2020 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2020-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2020-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2020-12-31 | $0 |
| Total income from all sources (including contributions) | 2020-12-31 | $103,321,900 |
| Total loss/gain on sale of assets | 2020-12-31 | $0 |
| Total of all expenses incurred | 2020-12-31 | $30,784,715 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2020-12-31 | $29,196,611 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2020-12-31 | $9,902,585 |
| Value of total assets at end of year | 2020-12-31 | $620,938,208 |
| Value of total assets at beginning of year | 2020-12-31 | $548,401,023 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2020-12-31 | $1,588,104 |
| Total interest from all sources | 2020-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2020-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2020-12-31 | No |
| Was this plan covered by a fidelity bond | 2020-12-31 | Yes |
| Value of fidelity bond cover | 2020-12-31 | $10,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2020-12-31 | No |
| Administrative expenses (other) incurred | 2020-12-31 | $1,588,104 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2020-12-31 | No |
| Value of net income/loss | 2020-12-31 | $72,537,185 |
| Value of net assets at end of year (total assets less liabilities) | 2020-12-31 | $620,938,208 |
| Value of net assets at beginning of year (total assets less liabilities) | 2020-12-31 | $548,401,023 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2020-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2020-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2020-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2020-12-31 | $618,250,559 |
| Value of interest in master investment trust accounts at beginning of year | 2020-12-31 | $545,414,696 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2020-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2020-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2020-12-31 | No |
| Contributions received in cash from employer | 2020-12-31 | $9,902,585 |
| Employer contributions (assets) at end of year | 2020-12-31 | $2,687,649 |
| Employer contributions (assets) at beginning of year | 2020-12-31 | $2,986,327 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2020-12-31 | $29,196,611 |
| Did the plan have assets held for investment | 2020-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2020-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2020-12-31 | No |
| Opinion of an independent qualified public accountant for this plan | 2020-12-31 | Disclaimer |
| Accountancy firm name | 2020-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2020-12-31 | 450250958 |
| 2019 : NORTHWESTERN ENERGY PENSION PLAN 2019 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2019-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2019-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2019-12-31 | $0 |
| Total income from all sources (including contributions) | 2019-12-31 | $110,082,941 |
| Total loss/gain on sale of assets | 2019-12-31 | $0 |
| Total of all expenses incurred | 2019-12-31 | $28,261,720 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2019-12-31 | $26,699,284 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2019-12-31 | $11,901,327 |
| Value of total assets at end of year | 2019-12-31 | $548,401,023 |
| Value of total assets at beginning of year | 2019-12-31 | $466,579,802 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2019-12-31 | $1,562,436 |
| Total interest from all sources | 2019-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2019-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2019-12-31 | No |
| Was this plan covered by a fidelity bond | 2019-12-31 | Yes |
| Value of fidelity bond cover | 2019-12-31 | $10,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2019-12-31 | No |
| Administrative expenses (other) incurred | 2019-12-31 | $1,562,436 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2019-12-31 | No |
| Value of net income/loss | 2019-12-31 | $81,821,221 |
| Value of net assets at end of year (total assets less liabilities) | 2019-12-31 | $548,401,023 |
| Value of net assets at beginning of year (total assets less liabilities) | 2019-12-31 | $466,579,802 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2019-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2019-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2019-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2019-12-31 | $545,414,696 |
| Value of interest in master investment trust accounts at beginning of year | 2019-12-31 | $466,494,802 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2019-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2019-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2019-12-31 | No |
| Contributions received in cash from employer | 2019-12-31 | $11,901,327 |
| Employer contributions (assets) at end of year | 2019-12-31 | $2,986,327 |
| Employer contributions (assets) at beginning of year | 2019-12-31 | $85,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2019-12-31 | $26,699,284 |
| Did the plan have assets held for investment | 2019-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2019-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2019-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2019-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2019-12-31 | Disclaimer |
| Accountancy firm name | 2019-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2019-12-31 | 450250958 |
| 2018 : NORTHWESTERN ENERGY PENSION PLAN 2018 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2018-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2018-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2018-12-31 | $0 |
| Total income from all sources (including contributions) | 2018-12-31 | $-36,330,161 |
| Total loss/gain on sale of assets | 2018-12-31 | $0 |
| Total of all expenses incurred | 2018-12-31 | $27,620,058 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2018-12-31 | $26,092,932 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2018-12-31 | $85,000 |
| Value of total assets at end of year | 2018-12-31 | $466,579,802 |
| Value of total assets at beginning of year | 2018-12-31 | $530,530,021 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2018-12-31 | $1,527,126 |
| Total interest from all sources | 2018-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2018-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2018-12-31 | No |
| Was this plan covered by a fidelity bond | 2018-12-31 | Yes |
| Value of fidelity bond cover | 2018-12-31 | $5,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2018-12-31 | No |
| Administrative expenses (other) incurred | 2018-12-31 | $1,527,126 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2018-12-31 | No |
| Value of net income/loss | 2018-12-31 | $-63,950,219 |
| Value of net assets at end of year (total assets less liabilities) | 2018-12-31 | $466,579,802 |
| Value of net assets at beginning of year (total assets less liabilities) | 2018-12-31 | $530,530,021 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2018-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2018-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2018-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2018-12-31 | $466,494,802 |
| Value of interest in master investment trust accounts at beginning of year | 2018-12-31 | $522,530,021 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2018-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2018-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2018-12-31 | No |
| Contributions received in cash from employer | 2018-12-31 | $85,000 |
| Employer contributions (assets) at end of year | 2018-12-31 | $85,000 |
| Employer contributions (assets) at beginning of year | 2018-12-31 | $8,000,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2018-12-31 | $26,092,932 |
| Did the plan have assets held for investment | 2018-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2018-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2018-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2018-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2018-12-31 | Disclaimer |
| Accountancy firm name | 2018-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2018-12-31 | 450250958 |
| 2017 : NORTHWESTERN ENERGY PENSION PLAN 2017 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2017-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2017-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2017-12-31 | $0 |
| Total income from all sources (including contributions) | 2017-12-31 | $84,085,627 |
| Total loss/gain on sale of assets | 2017-12-31 | $0 |
| Total of all expenses incurred | 2017-12-31 | $24,984,992 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2017-12-31 | $23,465,494 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2017-12-31 | $9,500,000 |
| Value of total assets at end of year | 2017-12-31 | $530,530,021 |
| Value of total assets at beginning of year | 2017-12-31 | $471,429,386 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2017-12-31 | $1,519,498 |
| Total interest from all sources | 2017-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2017-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2017-12-31 | No |
| Was this plan covered by a fidelity bond | 2017-12-31 | Yes |
| Value of fidelity bond cover | 2017-12-31 | $5,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2017-12-31 | No |
| Administrative expenses (other) incurred | 2017-12-31 | $1,519,498 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2017-12-31 | No |
| Value of net income/loss | 2017-12-31 | $59,100,635 |
| Value of net assets at end of year (total assets less liabilities) | 2017-12-31 | $530,530,021 |
| Value of net assets at beginning of year (total assets less liabilities) | 2017-12-31 | $471,429,386 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2017-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2017-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2017-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2017-12-31 | $522,530,021 |
| Value of interest in master investment trust accounts at beginning of year | 2017-12-31 | $464,929,386 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2017-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2017-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2017-12-31 | No |
| Contributions received in cash from employer | 2017-12-31 | $9,500,000 |
| Employer contributions (assets) at end of year | 2017-12-31 | $8,000,000 |
| Employer contributions (assets) at beginning of year | 2017-12-31 | $6,500,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2017-12-31 | $23,465,494 |
| Did the plan have assets held for investment | 2017-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2017-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2017-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2017-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2017-12-31 | Disclaimer |
| Accountancy firm name | 2017-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2017-12-31 | 450250958 |
| 2016 : NORTHWESTERN ENERGY PENSION PLAN 2016 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2016-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2016-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2016-12-31 | $0 |
| Total income from all sources (including contributions) | 2016-12-31 | $45,859,996 |
| Total loss/gain on sale of assets | 2016-12-31 | $0 |
| Total of all expenses incurred | 2016-12-31 | $25,864,218 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2016-12-31 | $24,376,950 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2016-12-31 | $9,000,000 |
| Value of total assets at end of year | 2016-12-31 | $471,429,386 |
| Value of total assets at beginning of year | 2016-12-31 | $451,433,608 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2016-12-31 | $1,487,268 |
| Total interest from all sources | 2016-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2016-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2016-12-31 | No |
| Was this plan covered by a fidelity bond | 2016-12-31 | Yes |
| Value of fidelity bond cover | 2016-12-31 | $5,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2016-12-31 | No |
| Administrative expenses (other) incurred | 2016-12-31 | $1,487,268 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2016-12-31 | No |
| Value of net income/loss | 2016-12-31 | $19,995,778 |
| Value of net assets at end of year (total assets less liabilities) | 2016-12-31 | $471,429,386 |
| Value of net assets at beginning of year (total assets less liabilities) | 2016-12-31 | $451,433,608 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2016-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2016-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2016-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2016-12-31 | $464,929,386 |
| Value of interest in master investment trust accounts at beginning of year | 2016-12-31 | $442,433,608 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2016-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2016-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2016-12-31 | No |
| Contributions received in cash from employer | 2016-12-31 | $9,000,000 |
| Employer contributions (assets) at end of year | 2016-12-31 | $6,500,000 |
| Employer contributions (assets) at beginning of year | 2016-12-31 | $9,000,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2016-12-31 | $24,376,950 |
| Did the plan have assets held for investment | 2016-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2016-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2016-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2016-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2016-12-31 | Disclaimer |
| Accountancy firm name | 2016-12-31 | EIDE BAILLY, LLP |
| Accountancy firm EIN | 2016-12-31 | 450250958 |
| 2015 : NORTHWESTERN ENERGY PENSION PLAN 2015 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2015-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2015-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2015-12-31 | $0 |
| Total income from all sources (including contributions) | 2015-12-31 | $-4,224,967 |
| Total loss/gain on sale of assets | 2015-12-31 | $0 |
| Total of all expenses incurred | 2015-12-31 | $49,201,264 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2015-12-31 | $47,774,364 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2015-12-31 | $9,000,000 |
| Value of total assets at end of year | 2015-12-31 | $451,433,608 |
| Value of total assets at beginning of year | 2015-12-31 | $504,859,839 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2015-12-31 | $1,426,900 |
| Total interest from all sources | 2015-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2015-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2015-12-31 | No |
| Was this plan covered by a fidelity bond | 2015-12-31 | Yes |
| Value of fidelity bond cover | 2015-12-31 | $3,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2015-12-31 | No |
| Administrative expenses (other) incurred | 2015-12-31 | $1,426,900 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2015-12-31 | No |
| Value of net income/loss | 2015-12-31 | $-53,426,231 |
| Value of net assets at end of year (total assets less liabilities) | 2015-12-31 | $451,433,608 |
| Value of net assets at beginning of year (total assets less liabilities) | 2015-12-31 | $504,859,839 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2015-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2015-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2015-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2015-12-31 | $442,433,608 |
| Value of interest in master investment trust accounts at beginning of year | 2015-12-31 | $495,859,839 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2015-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2015-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2015-12-31 | No |
| Contributions received in cash from employer | 2015-12-31 | $9,000,000 |
| Employer contributions (assets) at end of year | 2015-12-31 | $9,000,000 |
| Employer contributions (assets) at beginning of year | 2015-12-31 | $9,000,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2015-12-31 | $47,774,364 |
| Did the plan have assets held for investment | 2015-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2015-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2015-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2015-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2015-12-31 | Disclaimer |
| Accountancy firm name | 2015-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2015-12-31 | 450250958 |
| 2014 : NORTHWESTERN ENERGY PENSION PLAN 2014 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2014-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2014-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2014-12-31 | $0 |
| Total income from all sources (including contributions) | 2014-12-31 | $57,215,645 |
| Total loss/gain on sale of assets | 2014-12-31 | $0 |
| Total of all expenses incurred | 2014-12-31 | $21,597,952 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2014-12-31 | $21,027,410 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2014-12-31 | $9,000,000 |
| Value of total assets at end of year | 2014-12-31 | $504,859,839 |
| Value of total assets at beginning of year | 2014-12-31 | $469,242,146 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2014-12-31 | $570,542 |
| Total interest from all sources | 2014-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2014-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2014-12-31 | No |
| Administrative expenses professional fees incurred | 2014-12-31 | $11,566 |
| Was this plan covered by a fidelity bond | 2014-12-31 | Yes |
| Value of fidelity bond cover | 2014-12-31 | $3,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2014-12-31 | No |
| Administrative expenses (other) incurred | 2014-12-31 | $558,976 |
| Liabilities. Value of operating payables at beginning of year | 2014-12-31 | $0 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2014-12-31 | No |
| Value of net income/loss | 2014-12-31 | $35,617,693 |
| Value of net assets at end of year (total assets less liabilities) | 2014-12-31 | $504,859,839 |
| Value of net assets at beginning of year (total assets less liabilities) | 2014-12-31 | $469,242,146 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2014-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2014-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2014-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2014-12-31 | $495,859,839 |
| Value of interest in master investment trust accounts at beginning of year | 2014-12-31 | $460,242,146 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2014-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2014-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2014-12-31 | No |
| Contributions received in cash from employer | 2014-12-31 | $9,000,000 |
| Employer contributions (assets) at end of year | 2014-12-31 | $9,000,000 |
| Employer contributions (assets) at beginning of year | 2014-12-31 | $9,000,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2014-12-31 | $21,027,410 |
| Liabilities. Value of benefit claims payable at beginning of year | 2014-12-31 | $0 |
| Did the plan have assets held for investment | 2014-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2014-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2014-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2014-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2014-12-31 | Disclaimer |
| Accountancy firm name | 2014-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2014-12-31 | 450250958 |
| 2013 : NORTHWESTERN ENERGY PENSION PLAN 2013 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2013-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2013-12-31 | $0 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2013-12-31 | $19,453 |
| Total income from all sources (including contributions) | 2013-12-31 | $59,734,565 |
| Total loss/gain on sale of assets | 2013-12-31 | $0 |
| Total of all expenses incurred | 2013-12-31 | $19,895,246 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2013-12-31 | $19,314,999 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2013-12-31 | $10,500,000 |
| Value of total assets at end of year | 2013-12-31 | $469,242,146 |
| Value of total assets at beginning of year | 2013-12-31 | $429,422,280 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2013-12-31 | $580,247 |
| Total interest from all sources | 2013-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2013-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2013-12-31 | No |
| Administrative expenses professional fees incurred | 2013-12-31 | $14,273 |
| Was this plan covered by a fidelity bond | 2013-12-31 | Yes |
| Value of fidelity bond cover | 2013-12-31 | $3,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2013-12-31 | No |
| Administrative expenses (other) incurred | 2013-12-31 | $565,974 |
| Liabilities. Value of operating payables at end of year | 2013-12-31 | $0 |
| Liabilities. Value of operating payables at beginning of year | 2013-12-31 | $4,587 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2013-12-31 | No |
| Value of net income/loss | 2013-12-31 | $39,839,319 |
| Value of net assets at end of year (total assets less liabilities) | 2013-12-31 | $469,242,146 |
| Value of net assets at beginning of year (total assets less liabilities) | 2013-12-31 | $429,402,827 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2013-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2013-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2013-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2013-12-31 | $460,242,146 |
| Value of interest in master investment trust accounts at beginning of year | 2013-12-31 | $420,422,280 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2013-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2013-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2013-12-31 | No |
| Contributions received in cash from employer | 2013-12-31 | $10,500,000 |
| Employer contributions (assets) at end of year | 2013-12-31 | $9,000,000 |
| Employer contributions (assets) at beginning of year | 2013-12-31 | $9,000,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2013-12-31 | $19,314,999 |
| Liabilities. Value of benefit claims payable at end of year | 2013-12-31 | $0 |
| Liabilities. Value of benefit claims payable at beginning of year | 2013-12-31 | $14,866 |
| Did the plan have assets held for investment | 2013-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2013-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2013-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2013-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2013-12-31 | Disclaimer |
| Accountancy firm name | 2013-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2013-12-31 | 450250958 |
| 2012 : NORTHWESTERN ENERGY PENSION PLAN 2012 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2012-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2012-12-31 | $19,453 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2012-12-31 | $8,608 |
| Total income from all sources (including contributions) | 2012-12-31 | $53,385,538 |
| Total loss/gain on sale of assets | 2012-12-31 | $0 |
| Total of all expenses incurred | 2012-12-31 | $19,269,361 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2012-12-31 | $18,824,001 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2012-12-31 | $9,000,000 |
| Value of total assets at end of year | 2012-12-31 | $429,422,280 |
| Value of total assets at beginning of year | 2012-12-31 | $395,295,258 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2012-12-31 | $445,360 |
| Total interest from all sources | 2012-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2012-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2012-12-31 | No |
| Administrative expenses professional fees incurred | 2012-12-31 | $23,553 |
| Was this plan covered by a fidelity bond | 2012-12-31 | Yes |
| Value of fidelity bond cover | 2012-12-31 | $3,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2012-12-31 | No |
| Administrative expenses (other) incurred | 2012-12-31 | $421,807 |
| Liabilities. Value of operating payables at end of year | 2012-12-31 | $4,587 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2012-12-31 | No |
| Value of net income/loss | 2012-12-31 | $34,116,177 |
| Value of net assets at end of year (total assets less liabilities) | 2012-12-31 | $429,402,827 |
| Value of net assets at beginning of year (total assets less liabilities) | 2012-12-31 | $395,286,650 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2012-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2012-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2012-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2012-12-31 | $420,422,280 |
| Value of interest in master investment trust accounts at beginning of year | 2012-12-31 | $384,795,258 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2012-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2012-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2012-12-31 | No |
| Contributions received in cash from employer | 2012-12-31 | $9,000,000 |
| Employer contributions (assets) at end of year | 2012-12-31 | $9,000,000 |
| Employer contributions (assets) at beginning of year | 2012-12-31 | $10,500,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2012-12-31 | $18,824,001 |
| Liabilities. Value of benefit claims payable at end of year | 2012-12-31 | $14,866 |
| Liabilities. Value of benefit claims payable at beginning of year | 2012-12-31 | $8,608 |
| Did the plan have assets held for investment | 2012-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2012-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2012-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2012-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2012-12-31 | Disclaimer |
| Accountancy firm name | 2012-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2012-12-31 | 450250958 |
| 2011 : NORTHWESTERN ENERGY PENSION PLAN 2011 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2011-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2011-12-31 | $8,608 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2011-12-31 | $17,199 |
| Total income from all sources (including contributions) | 2011-12-31 | $23,513,186 |
| Total loss/gain on sale of assets | 2011-12-31 | $0 |
| Total of all expenses incurred | 2011-12-31 | $19,519,068 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2011-12-31 | $19,405,355 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2011-12-31 | $10,500,000 |
| Value of total assets at end of year | 2011-12-31 | $395,295,258 |
| Value of total assets at beginning of year | 2011-12-31 | $391,309,731 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2011-12-31 | $113,713 |
| Total interest from all sources | 2011-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2011-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2011-12-31 | No |
| Administrative expenses professional fees incurred | 2011-12-31 | $4,128 |
| Was this plan covered by a fidelity bond | 2011-12-31 | Yes |
| Value of fidelity bond cover | 2011-12-31 | $3,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2011-12-31 | No |
| Administrative expenses (other) incurred | 2011-12-31 | $109,585 |
| Liabilities. Value of operating payables at beginning of year | 2011-12-31 | $17,199 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2011-12-31 | No |
| Value of net income/loss | 2011-12-31 | $3,994,118 |
| Value of net assets at end of year (total assets less liabilities) | 2011-12-31 | $395,286,650 |
| Value of net assets at beginning of year (total assets less liabilities) | 2011-12-31 | $391,292,532 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2011-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2011-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2011-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2011-12-31 | $384,795,258 |
| Value of interest in master investment trust accounts at beginning of year | 2011-12-31 | $380,809,731 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2011-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2011-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2011-12-31 | No |
| Contributions received in cash from employer | 2011-12-31 | $10,500,000 |
| Employer contributions (assets) at end of year | 2011-12-31 | $10,500,000 |
| Employer contributions (assets) at beginning of year | 2011-12-31 | $10,500,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2011-12-31 | $19,405,355 |
| Liabilities. Value of benefit claims payable at end of year | 2011-12-31 | $8,608 |
| Did the plan have assets held for investment | 2011-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2011-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2011-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2011-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2011-12-31 | Disclaimer |
| Accountancy firm name | 2011-12-31 | EIDE BAILLY LLP |
| Accountancy firm EIN | 2011-12-31 | 450250958 |
| 2010 : NORTHWESTERN ENERGY PENSION PLAN 2010 401k financial data |
|---|
| Total unrealized appreciation/depreciation of assets | 2010-12-31 | $0 |
| Total liabilities at end of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2010-12-31 | $17,199 |
| Total liabilities at beginning of year (benefit claims payable, operating payabales, acquisition indebtedness and other liabilities) | 2010-12-31 | $434 |
| Total income from all sources (including contributions) | 2010-12-31 | $53,869,813 |
| Total loss/gain on sale of assets | 2010-12-31 | $0 |
| Total of all expenses incurred | 2010-12-31 | $17,703,322 |
| Benefit payments and payments to participlants,beneficiaries,insurance carriers and others | 2010-12-31 | $17,539,957 |
| Total contributions o plan (from employers,participants, others, non cash contrinutions) | 2010-12-31 | $10,500,000 |
| Value of total assets at end of year | 2010-12-31 | $391,309,731 |
| Value of total assets at beginning of year | 2010-12-31 | $355,126,475 |
| Total of administrative expenses incurred including professional, contract, advisory and management fees | 2010-12-31 | $163,365 |
| Total interest from all sources | 2010-12-31 | $0 |
| Total dividends received (eg from common stock, registered investment company shares) | 2010-12-31 | $0 |
| Has a resolution to terminate the plan been adopted during the plan year or any prior plan year | 2010-12-31 | No |
| Administrative expenses professional fees incurred | 2010-12-31 | $52,065 |
| Was this plan covered by a fidelity bond | 2010-12-31 | Yes |
| Value of fidelity bond cover | 2010-12-31 | $3,000,000 |
| Were there any nonexempt tranactions with any party-in-interest | 2010-12-31 | No |
| Administrative expenses (other) incurred | 2010-12-31 | $111,300 |
| Liabilities. Value of operating payables at end of year | 2010-12-31 | $17,199 |
| Liabilities. Value of operating payables at beginning of year | 2010-12-31 | $434 |
| Did the receive any noncash contributions whose value was neither redily determinable on an established market nor set by an independent third party appraiser | 2010-12-31 | No |
| Value of net income/loss | 2010-12-31 | $36,166,491 |
| Value of net assets at end of year (total assets less liabilities) | 2010-12-31 | $391,292,532 |
| Value of net assets at beginning of year (total assets less liabilities) | 2010-12-31 | $355,126,041 |
| Did the plan have a loss casued by fraud or dishonesty (regardless whether reimbursed by fidelity bond) | 2010-12-31 | No |
| Were any loans by the plan or fixed income obligations due to the plan in default | 2010-12-31 | No |
| Were any leases to which the plan was party in default or uncollectible | 2010-12-31 | No |
| Value of interest in master investment trust accounts at end of year | 2010-12-31 | $380,809,731 |
| Value of interest in master investment trust accounts at beginning of year | 2010-12-31 | $346,126,475 |
| Net investment gain or loss from common/collective trusts | 2010-12-31 | $43,369,813 |
| Were any plan transactions or series of transactions in excess of 5% of the current value of the plan assets | 2010-12-31 | No |
| Was there a failure to transmit to the plan any participant contributions | 2010-12-31 | No |
| Has the plan failed to provide any benefit when due under the plan | 2010-12-31 | No |
| Contributions received in cash from employer | 2010-12-31 | $10,500,000 |
| Employer contributions (assets) at end of year | 2010-12-31 | $10,500,000 |
| Employer contributions (assets) at beginning of year | 2010-12-31 | $9,000,000 |
| Benefit payments and payments to provide benefits directly to participlants or beneficiaries including direct rollovers | 2010-12-31 | $17,539,957 |
| Did the plan have assets held for investment | 2010-12-31 | No |
| Did the plan hold any assets whose current value was neither redily determinable on an established market nor set by an independent third party appraiser | 2010-12-31 | No |
| Were all the plan assets eitehr distributed to particpants/beneficiaries, transferred to another plan or brought under the control of the PBGC | 2010-12-31 | No |
| Accountant perfomed limited scope audit pursuant to 29 CFR 2520.103-8 and/or 103-12(d) | 2010-12-31 | Yes |
| Opinion of an independent qualified public accountant for this plan | 2010-12-31 | Disclaimer |
| Accountancy firm name | 2010-12-31 | EIDE BAILLY, LLP |
| Accountancy firm EIN | 2010-12-31 | 450250958 |
