Benefit Plans - Components of Company Plan Benefit Expense (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Change in Projected Benefit Obligation
Projected benefit obligation, beginning of period	$ 33,530	$ 37,551	$ 37,551
Service cost	351	313	1,254
Interest cost	319	326	1,306
Actuarial gain	0		3,180
Other reclassification	0		(8,925)
Benefits paid	(216)		(836)
Projected benefit obligation, end of period	33,984		33,530
Change in Plan Assets
Plan assets at fair value, beginning of period	0	$ 0	0
Company contributions	216		836
Benefits paid	(216)		(836)
Plan assets at fair value, end of period	0		0
Unfunded Status of the Plan	$ 33,984		$ 33,530