Employee Benefit Plans (Reconciliation of Changes in Fair Value of Plan Assets, Plan Benefit Obligations and Funded Status) (Details) - Employee Pension Plans [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in Fair Value of Plan Assets
Balance at beginning of year	$ 63,109	$ 71,541
Actual return on plan assets	12,123	(4,758)
Company contribution	4,793	2,975
Benefit payments	(6,668)	(6,649)
Balance at end of year	73,357	63,109	$ 71,541
Change in Benefit Obligations
Balance at beginning of year	95,869	106,218
Interest cost	3,801	3,496	3,919
Service cost	900	875	850
Assumption change loss (gain)	8,373	(7,056)
Actuarial loss (gain)	332	(1,014)
Benefit payments	(6,668)	(6,650)
Balance at end of year	$ 102,607	$ 95,869	$ 106,218