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Employee Postretirement Benefits - Amounts Recognized in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Pension Benefits (Pension Plan) |  |
Regulatory Assets (Liabilities): |  |
Unrecognized Prior Service Cost | $ 0 | $ 0
Unrecognized Actuarial Loss | 85,367 | 102,737
Net Regulatory Assets (Liabilities) | 85,367 | 102,737
Accumulated Other Comprehensive Income (Loss): |  |
Unrecognized Prior Service Cost | 0 | 0
Unrecognized Actuarial (Gain) Loss | (1,978) | (1,020)
Total Accumulated Other Comprehensive Income (Loss) | (1,978) | (1,020)
Pension Benefits (ESSRP) |  |
Regulatory Assets (Liabilities): |  |
Unrecognized Prior Service Cost | 0 | 0
Unrecognized Actuarial Loss | 979 | 2,525
Net Regulatory Assets (Liabilities) | 979 | 2,525
Accumulated Other Comprehensive Income (Loss): |  |
Unrecognized Prior Service Cost | 0 | 0
Unrecognized Actuarial (Gain) Loss | 1,093 | 10,660
Total Accumulated Other Comprehensive Income (Loss) | 1,093 | 10,660
Postretirement Benefits |  |
Regulatory Assets (Liabilities): |  |
Unrecognized Prior Service Cost | (8,400) | (13,989)
Unrecognized Actuarial Loss | 3,993 | 26,852
Net Regulatory Assets (Liabilities) | (4,407) | 12,863
Accumulated Other Comprehensive Income (Loss): |  |
Unrecognized Prior Service Cost | (99) | (242)
Unrecognized Actuarial (Gain) Loss | (818) | (160)
Total Accumulated Other Comprehensive Income (Loss) | $ (917) | $ (402)

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- Definition Represents unrecognized actuarial net gains (losses) pertaining to regulatory assets under a defined benefit plan. + References No definition available. + Details
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- Definition Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (i-k) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669646-108580 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (j) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
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- Definition Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (j) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580 + Details
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- Definition Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (j) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669686-108580 + Details
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