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Regulatory Matters - Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2022 | Dec. 31, 2021
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | $ 21,770 | $ 27,342
Regulatory assets, long-term | 124,413 | 125,508
Regulatory liabilities, current | 27,211 | 24,844
Regulatory liabilities, long -term | 233,989 | 234,430
Deferred Income Taxes |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory liabilities, current | 0 | 0
Regulatory liabilities, long -term | 128,042 | 129,437
Plant Removal Obligations |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory liabilities, current | 8,561 | 8,306
Regulatory liabilities, long -term | 101,850 | 101,595
Fuel Clause Adjustments |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory liabilities, current | 5,386 | 1,554
Regulatory liabilities, long -term | $ 0 | 0
Regulatory Liabilities - Remaining Recovery/Refund Period | 1 year |
Alternative Revenue Program Riders |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory liabilities, current | $ 6,215 | 5,772
Regulatory liabilities, long -term | 3,986 | 3,336
Pension and Other Postretirement Benefit Plans |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory liabilities, current | 2,603 | 2,603
Regulatory liabilities, long -term | $ 0 | 0
Regulatory Liabilities - Remaining Recovery/Refund Period | 1 year |
Derivative Instruments |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory liabilities, current | $ 4,179 | 6,214
Regulatory liabilities, long -term | 0 | 0
Other |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory liabilities, current | 267 | 395
Regulatory liabilities, long -term | 111 | 62
Pension and Other Postretirement Benefit Plans |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | 7,791 | 7,791
Regulatory assets, long-term | 113,663 | 114,961
Alternative Revenue Program Riders |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | 9,280 | 11,889
Regulatory assets, long-term | $ 5,713 | 5,564
Regulatory Assets - Remaining Recovery/Refund Period | 2 years |
Asset Retirement Obligations |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | $ 0 | 0
Regulatory assets, long-term | 1,098 | 742
ISO Cost Recovery Trackers |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | 220 | 0
Regulatory assets, long-term | $ 950 | 1,342
Regulatory Assets - Remaining Recovery/Refund Period | 2 years |
Unrecovered Project Costs |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | $ 1,086 | 2,136
Regulatory assets, long-term | $ 1,456 | 1,455
Regulatory Assets - Remaining Recovery/Refund Period | 5 years |
Deferred Rate Case Expenses |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | $ 542 | 607
Regulatory assets, long-term | 1,037 | 1,131
Debt Reacquisition Premiums |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | 68 | 100
Regulatory assets, long-term | $ 234 | 240
Regulatory Assets - Remaining Recovery/Refund Period | 11 years |
Fuel Clause Adjustments |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | $ 2,767 | 4,819
Regulatory assets, long-term | 0 | 0
Other |  |
Schedule of Regulatory Assets and Liabilities [Line Items] |  |
Regulatory assets - current | 16 | 0
Regulatory assets, long-term | $ 262 | $ 73

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- Definition Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
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