Employee Benefit Plans (Changes in Fair Value of Plan Assets and Plan Benefit Obligations and Funded Status of Plan) (Details) - Employee Pension Plans [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in Fair Value of Plan Assets
Balance at beginning of year	$ 71,541	$ 66,057
Actual return on plan assets	(4,758)	9,224
Company contribution	2,975	2,838
Benefit payments	(6,649)	(6,578)
Balance at end of year	63,109	71,541	$ 66,057
Change in Benefit Obligations
Balance at beginning of year	106,218	103,681
Interest cost	3,496	3,919	4,153
Service cost	875	850	600
Assumption change (gain) loss	(7,056)	3,854
Actuarial (gain) loss	(1,014)	492
Benefit payments	(6,650)	(6,578)
Balance at end of year	$ 95,869	$ 106,218	$ 103,681