Employee Benefit Plans (Schedule of Change in Fair Value of Plan Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pension Benefit Plan [Member]
Change in Fair Value of Plan Assets:
Beginning Balance	$ 52,931	$ 51,623
Actual Return on Plan Assets	4,909	11
Employer Contributions	3,635	3,335
Benefits Paid	(2,105)	(2,038)
Ending Balance	59,370	52,931
Funded Status	(19,231)	(19,611)
Other Benefits Plan [Member]
Change in Fair Value of Plan Assets:
Beginning Balance	29,018	27,535
Actual Return on Plan Assets	1,591	350
Employer Contributions	1,551	1,694
Benefits Paid	(553)	(561)
Ending Balance	31,607	29,018
Funded Status	$ (17,281)	$ (17,231)