Accumulated Other Comprehensive Loss (Components of AOCI) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 4,057		$ (100,176)		$ (25,268)		$ (82,106)
Other comprehensive (loss) income before reclassifications	(6,418)		2,394		20,954		(20,907)
Amounts reclassified from accumulated other comprehensive income (loss)	503		2,237		2,456		7,468
Net current period other comprehensive (loss) income	(5,915)		4,631		23,410		(13,439)
Ending balance	(1,858)		(95,545)		(1,858)		(95,545)
Unrealized Loss on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(3,643)	[1]	(4,959)	[1]	(4,434)	[1]	(6,292)	[1]
Other comprehensive (loss) income before reclassifications	582	[1]	101	[1]	1,373	[1]	1,434	[1]
Amounts reclassified from accumulated other comprehensive income (loss)	0	[1]	0	[1]	0	[1]	0	[1]
Net current period other comprehensive (loss) income	582	[1]	101	[1]	1,373	[1]	1,434	[1]
Ending balance	(3,061)	[1]	(4,858)	[1]	(3,061)	[1]	(4,858)	[1]
Unrealized Gains on Investment Securities Available for Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	16,490	[1]	(4,117)	[1]	(10,091)	[1]	20,517	[1]
Other comprehensive (loss) income before reclassifications	(7,000)	[1]	2,293	[1]	19,581	[1]	(22,341)	[1]
Amounts reclassified from accumulated other comprehensive income (loss)	0	[1]	0	[1]	0	[1]	0	[1]
Net current period other comprehensive (loss) income	(7,000)	[1]	2,293	[1]	19,581	[1]	(22,341)	[1]
Ending balance	9,490	[1]	(1,824)	[1]	9,490	[1]	(1,824)	[1]
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(8,790)	[1]	(91,100)	[1]	(10,743)	[1]	(96,331)	[1]
Other comprehensive (loss) income before reclassifications	0	[1]	0	[1]	0	[1]	0	[1]
Amounts reclassified from accumulated other comprehensive income (loss)	503	[1]	2,237	[1]	2,456	[1]	7,468	[1]
Net current period other comprehensive (loss) income	503	[1]	2,237	[1]	2,456	[1]	7,468	[1]
Ending balance	$ (8,287)	[1]	$ (88,863)	[1]	$ (8,287)	[1]	$ (88,863)	[1]

[1] All amounts are net of tax.