Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Loss [Roll Forward]
Equity, beginning balance	$ 1,161,962	$ 2,099,808	$ 1,156,183	$ 2,130,825
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from AOCI, net of tax	34	25	68	50
Net current-period other comprehensive income (loss)	34	25	68	50
Equity, ending balance	1,168,185	1,428,189	1,168,185	1,428,189
Defined Benefit Pension Items
Accumulated Other Comprehensive Loss [Roll Forward]
Equity, beginning balance	(75,218)	(77,302)	(75,247)	(77,327)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from AOCI, net of tax	29	25	58	50
Net current-period other comprehensive income (loss)	29	25	58	50
Equity, ending balance	(75,189)	(77,277)	(75,189)	(77,277)
Tax on amount reclassified from AOCI	11	8	22	16
Other
Accumulated Other Comprehensive Loss [Roll Forward]
Equity, beginning balance	(258)	(144)	(263)	(144)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from AOCI, net of tax	5	0	10	0
Net current-period other comprehensive income (loss)	5	0	10	0
Equity, ending balance	(253)	(144)	(253)	(144)
AOCI Attributable to Parent
Accumulated Other Comprehensive Loss [Roll Forward]
Equity, beginning balance	(75,476)	(77,446)	(75,510)	(77,471)
Equity, ending balance	$ (75,442)	$ (77,421)	$ (75,442)	$ (77,421)