Other Comprehensive Income/Loss (Components of Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Comprehensive Income (Loss), After Reclassification Adjustments [Abstract]
Before Tax Amount	$ 1,428	$ (3,786)	$ 8,830	$ 241
Income Tax Benefit (Expense)	(577)	1,439	(3,569)	(97)
After Tax Amount	851	(2,347)	5,261	144
Net unrealized gain on securities available-for-sale
Other Comprehensive Income (Loss), Before Reclassifications [Abstract]
Before Tax Amount	852	(4,491)	7,626	(1,268)
Income Tax Benefit (Expense)	(345)	1,743	(3,083)	513
After Tax Amount	507	(2,748)	4,543	(755)
Other Comprehensive Income (Loss), Reclassifications Adjustments [Abstract]
Before Tax Amount		(72)	(86)	(72)
Income Tax Benefit (Expense)		29	35	29
After Tax Amount		(43)	(51)	(43)
Other Comprehensive Income (Loss), After Reclassification Adjustments [Abstract]
Before Tax Amount		(4,563)	7,540	(1,340)
Income Tax Benefit (Expense)		1,772	(3,048)	542
After Tax Amount		(2,791)	4,492	(798)
Net actuarial loss on pension plans and other postretirement benefits
Other Comprehensive Income (Loss), Reclassifications Adjustments [Abstract]
Before Tax Amount	528	729	1,195	1,486
Income Tax Benefit (Expense)	(213)	(312)	(483)	(600)
After Tax Amount	315	417	712	886
Prior service cost on pension plans and other postretirement benefits
Other Comprehensive Income (Loss), Reclassifications Adjustments [Abstract]
Before Tax Amount	48	48	95	95
Income Tax Benefit (Expense)	(19)	(21)	(38)	(39)
After Tax Amount	$ 29	$ 27	$ 57	$ 56