Benefit Plans - Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan
Amounts arising during the year:
Net (gain) loss on pension assets	$ 3,581	$ (4,839)	$ (16,278)
Net loss (gain) on pension obligations	(4,614)	14,935	21,512
Reclassification adjustments recognized as components of net periodic benefit cost during the year:
Net (gain) loss	(6,961)	(5,806)	(6,995)
Amount recognized in other comprehensive income	(7,994)	4,290	(1,761)
Other Benefits
Amounts arising during the year:
Net loss (gain) on pension obligations	(2,074)	303	540
Reclassification adjustments recognized as components of net periodic benefit cost during the year:
Net (gain) loss	48	211	385
Prior service credit		51	429
Amount recognized in other comprehensive income	$ (2,026)	$ 565	$ 1,354