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Regulatory liabilities (Details 2) - USD ($) $ in Thousands | 9 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2022 | Dec. 31, 2021 | Sep. 30, 2021
Regulatory Liabilities [Line Items] |  |  |
Regulatory liabilities due within one year | $ 18,599 | $ 16,303 | $ 16,491
Regulatory liabilities | 433,212 | 428,790 | 426,141
Total regulatory liabilities | 451,811 | 445,093 | 442,632
Net regulatory position | 40,791 | 31,449 | 69,748
Taxes refundable to customers |  |  |
Regulatory Liabilities [Line Items] |  |  |
Regulatory liabilities due within one year | 4,264 | 3,841 | 3,867
Regulatory liabilities | $ 205,517 | 215,421 | 218,566
Taxes refundable to customers | Minimum [Member] |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 1 year |  |
Taxes refundable to customers | Maximum [Member] |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Over plant lives |  |
Electric fuel and purchased power deferral |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 1 year |  |
Regulatory liabilities due within one year | $ 3,763 | 0 | 3,205
Cost Recovery Mechanisms |  |  |
Regulatory Liabilities [Line Items] |  |  |
Regulatory liabilities due within one year | 2,674 | 214 | 2,797
Regulatory liabilities | $ 12,535 | 7,727 | 0
Cost Recovery Mechanisms | Minimum [Member] |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 1 year |  |
Cost Recovery Mechanisms | Maximum [Member] |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 20 years |  |
Natural gas costs refundable through rate adjustments |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 1 year |  |
Regulatory liabilities due within one year | $ 873 | 6,700 | 0
Other regulatory liabilities |  |  |
Regulatory Liabilities [Line Items] |  |  |
Regulatory liabilities due within one year | 7,025 | 5,548 | 6,622
Regulatory liabilities | $ 6,327 | 4,360 | 5,574
Other regulatory liabilities | Minimum [Member] |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 1 year |  |
Other regulatory liabilities | Maximum [Member] |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 16 years |  |
Plant removal and decommissioning costs |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Over plant lives |  |
Regulatory liabilities | $ 174,481 | 168,152 | 172,683
Pension and postretirement benefits |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | ** |  |
Regulatory liabilities | $ 19,687 | 20,434 | 16,915
Accumulated Deferred ITC |  |  |
Regulatory Liabilities [Line Items] |  |  |
Estimated Recovery or Refund Period as of September 30, 2022 | Up to 20 years |  |
Regulatory liabilities | $ 14,665 | $ 12,696 | $ 12,403

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- Definition The net amount of all regulatory assets less all regulatory liabilities as of the end of the period. + 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 https://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
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