Other Comprehensive Income/Loss (Components of Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Other Comprehensive Income (Loss), After Reclassification Adjustments [Abstract]
Before Tax Amount	$ 7,402	$ 4,027
Income Tax Expense	(2,992)	(1,536)
After Tax Amount	4,410	2,491
Net unrealized gain on securities available-for-sale
Other Comprehensive Income (Loss), Before Reclassifications [Abstract]
Before Tax Amount	6,774	3,223
Income Tax Expense	(2,738)	(1,230)
After Tax Amount	4,036	1,993
Other Comprehensive Income (Loss), Reclassifications Adjustments [Abstract]
Before Tax Amount	(86)
Income Tax Expense	35
After Tax Amount	(51)
Other Comprehensive Income (Loss), After Reclassification Adjustments [Abstract]
Before Tax Amount	6,688
Income Tax Expense	(2,703)
After Tax Amount	3,985
Reclassification adjustment for net actuarial loss on pension plans and other postretirement benefits included in net income
Other Comprehensive Income (Loss), Reclassifications Adjustments [Abstract]
Before Tax Amount	667	757
Income Tax Expense	(270)	(288)
After Tax Amount	397	469
Reclassification adjustment for prior service cost on pension plans and other postretirement benefits included in net income
Other Comprehensive Income (Loss), Reclassifications Adjustments [Abstract]
Before Tax Amount	47	47
Income Tax Expense	(19)	(18)
After Tax Amount	$ 28	$ 29