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Benefit Plans (Details) - USD ($) $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended
--- | --- | --- | ---
Jul. 31, 2022 | Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021
Pension and Supplemental Executive Retirement Plans |  |  |  |  |
Components of Net Periodic Benefit Cost [Abstract] |  |  |  |  |
Service cost |  | $ 1,869 | $ 2,152 | $ 3,626 | $ 3,816
Interest cost |  | 2,848 | 2,779 | 5,725 | 5,589
Expected return on plan assets |  | (4,864) | (5,256) | (9,816) | (10,458)
Amortization of net actuarial losses (gains) |  | 1,349 | 1,255 | 2,532 | 2,805
Amortization of prior service cost (credit) |  | (53) | (59) | (106) | (119)
Net periodic benefit cost (benefit) |  | 1,149 | 871 | 1,961 | 1,633
Other Postretirement Benefit Plans |  |  |  |  |
Components of Net Periodic Benefit Cost [Abstract] |  |  |  |  |
Service cost |  | 306 | 390 | 654 | 754
Interest cost |  | 171 | 160 | 348 | 324
Expected return on plan assets |  | (2,626) | (2,216) | (5,251) | (4,431)
Amortization of net actuarial losses (gains) |  | (798) | (409) | (1,552) | (848)
Amortization of prior service cost (credit) |  | 122 | 53 | 244 | 106
Net periodic benefit cost (benefit) |  | $ (2,825) | $ (2,022) | $ (5,557) | $ (4,095)
Pension Plan | Subsequent Event |  |  |  |  |
Components of Net Periodic Benefit Cost [Abstract] |  |  |  |  |
Company contribution to qualified pension plan | $ 6,300 |  |  |  |

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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(3) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(3) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 + Details
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