Pension and Other Post-Retirement Benefit Plans (Fair Value Measurements Using Significant Level 3 Unobservable Inputs) (Details) - Level 3 [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule of Level Three Defined Benefit Plan Assets [Roll Forward]
Plan assets, beginning balance	$ 55,474	$ 48,900
Unrealized gains	5,078	8,872
Purchases & settlements	(2,186)	(2,298)
Plan assets, ending balance	58,366	55,474
Hedge Funds & Private Equity [Member]
Schedule of Level Three Defined Benefit Plan Assets [Roll Forward]
Plan assets, beginning balance	29,417	29,339
Unrealized gains	1,418	2,376
Purchases & settlements	(2,186)	(2,298)
Plan assets, ending balance	28,649	29,417
Real Estate Investments [Member]
Schedule of Level Three Defined Benefit Plan Assets [Roll Forward]
Plan assets, beginning balance	26,057	19,561
Unrealized gains	3,660	6,496
Purchases & settlements	0	0
Plan assets, ending balance	$ 29,717	$ 26,057