Employee Benefit Plans (Schedule of Changes in Fair Value of Plan Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets, Beginning Balance	$ 66,757
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	68,435	$ 66,757
Defined Benefit Plan, Funded Status of Plan	(73,804)	(71,439)
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets, Beginning Balance	66,757	59,559
Defined Benefit Plan, Actual Return on Plan Assets	(2,795)	2,489
Defined Benefit Plan, Contributions by Employer	8,953	7,753
Defined Benefit Plan, Contributions by Plan Participants	0	0
Defined Benefit Plan, Benefits Paid	(4,480)	(3,044)
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	68,435	66,757
Defined Benefit Plan, Funded Status of Plan	(73,804)	(71,439)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets, Beginning Balance	0	0
Defined Benefit Plan, Actual Return on Plan Assets	0	0
Defined Benefit Plan, Contributions by Employer	380	647
Defined Benefit Plan, Contributions by Plan Participants	229	174
Defined Benefit Plan, Benefits Paid	(609)	(821)
Defined Benefit Plan, Fair Value of Plan Assets, Ending Balance	0	0
Defined Benefit Plan, Funded Status of Plan	$ (63,307)	$ (59,782)