Accumulated Other Comprehensive Loss (Components of AOCI) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ (35,411)	$ (16,594)	$ (52,981)	$ (25,268)
Other comprehensive income before reclassifications		(17,439)	19,675	1,517	27,372
Amounts reclassified from accumulated other comprehensive (loss) income		1,691	976	305	1,953
Net current period other comprehensive income		(15,748)	20,651	1,822	29,325
Ending balance		(51,159)	4,057	(51,159)	4,057
Unrealized Loss on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]	(2,310)	(3,993)	(2,664)	(4,434)
Other comprehensive income before reclassifications	[1]	435	350	789	791
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	0	0	0	0
Net current period other comprehensive income	[1]	435	350	789	791
Ending balance	[1]	(1,875)	(3,643)	(1,875)	(3,643)
Unrealized Gains on Investment Securities Available for Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]	20,551	(2,835)	5,098	(10,091)
Other comprehensive income before reclassifications	[1]	(17,874)	19,325	728	26,581
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	(73)	0	(3,222)	0
Net current period other comprehensive income	[1]	(17,947)	19,325	(2,494)	26,581
Ending balance	[1]	2,604	16,490	2,604	16,490
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]	(53,652)	(9,766)	(55,415)	(10,743)
Other comprehensive income before reclassifications	[1]	0	0	0	0
Amounts reclassified from accumulated other comprehensive (loss) income	[1]	1,764	976	3,527	1,953
Net current period other comprehensive income	[1]	1,764	976	3,527	1,953
Ending balance	[1]	$ (51,888)	$ (8,790)	$ (51,888)	$ (8,790)

[1] All amounts are net of tax.