Benefit Plans - Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Pension
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 45,746	$ 53,400
Prior service cost	216	251
Deferred (benefit) tax expense	(12,697)	(15,116)
Total	33,265	38,535
OPEB
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(988)	(881)
Prior service cost	0	0
Deferred (benefit) tax expense	273	249
Total	$ (715)	$ (632)