Employee Benefit Plans (Reconciliation of Changes in Fair Value of Plan Assets, Plan Benefit Obligations and Funded Status) (Details) - Employee Pension Plans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in Fair Value of Plan Assets
Balance at beginning of year	$ 73,357	$ 63,109
Actual return on plan assets	899	12,123
Company contribution	4,408	4,793
Benefit payments	(6,724)	(6,668)
Balance at end of year	71,940	73,357	$ 63,109
Change in Benefit Obligations
Balance at beginning of year	102,607	95,869
Interest cost	3,032	3,801	3,496
Service cost	925	900	875
Assumption change loss	7,902	8,373
Actuarial loss	81	332
Benefit payments	(6,723)	(6,668)
Balance at end of year	$ 107,824	$ 102,607	$ 95,869