Pension and Other Postretirement Benefits - Amounts Recognized in Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Amounts recognized in the balance sheets:
Accrued benefit liability, noncurrent	$ (74,573)	$ (67,828)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Funded status, end of year	(41,381)	(36,092)
Amounts recognized in the balance sheets:
Prepaid benefit cost	16,358	16,251
Accrued benefit liability, current	(3,051)	(3,106)
Accrued benefit liability, noncurrent	(54,688)	(49,237)
Net funded status	(41,381)	(36,092)
Other Plans
Defined Benefit Plan Disclosure [Line Items]
Funded status, end of year	(21,312)	(19,944)
Amounts recognized in the balance sheets:
Prepaid benefit cost	0	0
Accrued benefit liability, current	(1,427)	(1,353)
Accrued benefit liability, noncurrent	(19,885)	(18,591)
Net funded status	$ (21,312)	$ (19,944)