Benefit Plans - Change in Net Actuarial Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Benefit Plans
Percentage of greater of projected benefit obligation or fair value of plan assets for amortization of actuarial gains or losses	5.00%
Amortization period for actuarial gains and losses that exceed threshold	5 years
Pension Plan
Change in net actuarial loss and amortization
Net actuarial loss (gain) at beginning of year	$ 44,351
Amortization cost	(6,961)	$ (5,806)	$ (6,995)
Liability loss (gain)	(4,614)	14,935	21,512
Asset (gain) loss	3,581	(4,839)	(16,278)
Net actuarial loss (gain) at end of year	36,357	44,351
Pension Benefits
Change in net actuarial loss and amortization
Net actuarial loss (gain) at beginning of year	44,351	40,061
Amortization cost	(6,961)	(5,806)
Liability loss (gain)	(4,614)	14,935
Asset (gain) loss	3,581	(4,839)
Net actuarial loss (gain) at end of year	36,357	44,351	40,061
Other Benefits
Change in net actuarial loss and amortization
Net actuarial loss (gain) at beginning of year	(1,068)	(1,582)
Amortization cost	48	211	385
Liability loss (gain)	(2,074)	303	540
Net actuarial loss (gain) at end of year	$ (3,094)	$ (1,068)	$ (1,582)