XML 31 R19.htm IDEA: XBRL DOCUMENT
v3.21.1

Regulatory assets and liabilities | 3 Months Ended
--- | ---
Mar. 31, 2021
Regulatory Assets and Liabilities Disclosure [Abstract] |
Regulatory Assets and Liabilities | Regulatory assets and liabilities The following table summarizes the individual components of unamortized regulatory assets and liabilities:
| Estimated Recovery or Refund Period as of March 31, 2021 | * | March 31, 2021 | March 31, 2020 | December 31, 2020 |  |
|  |  | (In thousands)
Regulatory assets: |  |  |  |  |  |  |
Current: |  |  |  |  |  |  |
Natural gas costs recoverable through rate adjustments | Up to 1 year |  | $ | 76,782 |  | $ | 39,805 |  | $ | 42,481 |  |  |
Cost recovery mechanisms | Up to 1 year |  | 7,130 |  | 6,686 |  | 10,645 |  |  |
Conservation programs | Up to 1 year |  | 6,679 |  | 6,303 |  | 7,117 |  |  |
Other | Up to 1 year |  | 7,861 |  | 2,412 |  | 8,284 |  |  |
|  |  | 98,452 |  | 55,206 |  | 68,527 |  |  |
Noncurrent: |  |  |  |  |  |  |
Pension and postretirement benefits | ** |  | 155,924 |  | 157,051 |  | 155,942 |  |  |
Plant retirement | - |  | 73,498 |  | 41,080 |  | 65,919 |  |  |
Plant costs/asset retirement obligations | Over plant lives |  | 72,250 |  | 67,475 |  | 71,740 |  |  |
Manufactured gas plant site remediation | - |  | 26,002 |  | 15,699 |  | 26,429 |  |  |
Cost recovery mechanisms | Up to 10 years |  | 15,508 |  | 11,891 |  | 16,245 |  |  |
Natural gas costs recoverable through rate adjustments | Up to 3 years |  | 15,158 |  | 33,027 |  | 21,539 |  |  |
Taxes recoverable from customers | Over plant lives |  | 10,800 |  | 11,082 |  | 10,785 |  |  |
Long-term debt refinancing costs | Up to 39 years |  | 4,268 |  | 4,133 |  | 4,426 |  |  |
Other | Up to 18 years |  | 6,509 |  | 6,751 |  | 6,356 |  |  |
|  |  | 379,917 |  | 348,189 |  | 379,381 |  |  |
Total regulatory assets |  |  | $ | 478,369 |  | $ | 403,395 |  | $ | 447,908 |  |  |
Regulatory liabilities: |  |  |  |  |  |  |
Current: |  |  |  |  |  |  |
Natural gas costs refundable through rate adjustments | Up to 1 year |  | $ | 16,344 |  | $ | 32,181 |  | $ | 18,565 |  |  |
Taxes refundable to customers | Up to 1 year |  | 3,092 |  | 4,002 |  | 3,557 |  |  |
Electric fuel and purchased power deferral | Up to 1 year |  | 2,001 |  | 7,188 |  | 3,667 |  |  |
Other | Up to 1 year |  | 12,829 |  | 16,701 |  | 5,661 |  |  |
|  |  | 34,266 |  | 60,072 |  | 31,450 |  |  |
Noncurrent: |  |  |  |  |  |  |
Taxes refundable to customers | Over plant lives |  | 224,795 |  | 240,148 |  | 227,850 |  |  |
Plant removal and decommissioning costs | Over plant lives |  | 169,430 |  | 174,120 |  | 167,171 |  |  |
Pension and postretirement benefits | ** |  | 16,965 |  | 18,040 |  | 16,989 |  |  |
Other | Up to 21 years |  | 17,870 |  | 10,897 |  | 16,065 |  |  |
|  |  | 429,060 |  | 443,205 |  | 428,075 |  |  |
Total regulatory liabilities |  |  | $ | 463,326 |  | $ | 503,277 |  | $ | 459,525 |  |  |
Net regulatory position |  |  | $ | 15,043 |  | $ | (99,882) |  | $ | (11,617) |  |  |
*Estimated recovery or refund period for amounts currently being recovered or refunded in rates charged to customers. ** Recovered as expense is incurred or cash contributions are made.
At March 31, 2021 and 2020, and December 31, 2020, approximately $361.4 million, $285.8 million and $332.5 million, respectively, of regulatory assets were not earning a rate of return; however, these regulatory assets are expected to be recovered from customers in future rates. These assets are largely comprised of the unfunded portion of pension and postretirement benefits, asset retirement obligations, accelerated depreciation on plant to be retired and the estimated future cost of manufactured gas plant site remediation. In February 2021, a prolonged period of unseasonably cold temperatures in the central United States significantly increased the demand for electric and natural gas services and contributed to increased market prices. Overall, Montana-Dakota and Great Plains incurred approximately $44.0 million in increased natural gas costs in February 2021 in order to maintain services for its customers. The Company has filed out-of-cycle purchased gas adjustment requests in four out of five jurisdictions affected by this cold-weather event, as discussed in Note 19, and will continue to engage with its regulators to determine the appropriate recovery periods over which to recover the associated natural gas costs. In 2019, the Company experienced increased natural gas costs in Washington from the rupture of the Enbridge pipeline in Canada in late 2018. As a result, the Company requested, and the WUTC approved, recovery of the balance of natural gas costs recoverable related to this period of time over three years rather than its normal one-year recovery period. In February 2019, the Company announced the retirement of three aging coal-fired electric generating units. The Company has accelerated the depreciation related to these facilities in property, plant and equipment and has recorded the difference between the accelerated depreciation, in accordance with GAAP, and the depreciation approved for rate-making purposes as regulatory assets. The first unit ceased operations on March 31, 2021, and as discussed in Note 19, requests have been filed with the NDPSC and SDPUC to offset the savings associated with the cessation of operations of this unit with the amortization of the deferred regulatory assets. The remaining two units are expected to be retired in early 2022. The Company expects to recover the regulatory assets related to the plant retirements in future rates. If, for any reason, the Company's regulated businesses cease to meet the criteria for application of regulatory accounting for all or part of their operations, the regulatory assets and liabilities relating to those portions ceasing to meet such criteria would be removed from the balance sheet and included in the statement of income or accumulated other comprehensive income (loss) in the period in which the discontinuance of regulatory accounting occurs.

X
- References No definition available. + Details
Name: | us-gaap_RegulatoryAssetsAndLiabilitiesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for detailed information about regulatory assets and liabilities, including current and noncurrent assets created when regulatory agencies permit the deferral of costs to the balance sheet that would otherwise be required to appear on the company's income statement and would be charged against current expenses or revenues, as well as current and noncurrent liabilities created when regulatory agencies permit. + References No definition available. + Details
Name: | us-gaap_ScheduleOfRegulatoryAssetsAndLiabilitiesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration