Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Components of net periodic benefit cost (credit):
Service cost	$ 1,140	$ 1,347	$ 910
Interest cost	1,538	1,642	1,794
Expected return on plan assets	(2,375)	(2,323)	(1,972)
Amortization of net loss	245	176	95
Amortization of prior service cost	0	1	3
Effect of curtailment	(2,032)	0	0
Net periodic benefit cost (credit)	$ (1,484)	$ 843	$ 830