Other Comprehensive Income (Loss) (Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Accumulated other comprehensive income, balance	$ 4,101	$ 21,093	$ 57,158
Other comprehensive income (loss) before reclassifications	(43,717)	7,961	16,708
Amounts reclassified from accumulated other comprehensive income (loss)	(1,642)	(24,953)	(52,773)
Net current period other comprehensive income (loss)	(45,359)	(16,992)	(36,065)
Accumulated other comprehensive income, balance	(41,258)	4,101	21,093
Net Unrealized Gains (Losses) on Cash Flow Hedges [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Accumulated other comprehensive income, balance	(13,373)	(12,524)	(1,208)
Other comprehensive income (loss) before reclassifications	0	0	(4,279)
Amounts reclassified from accumulated other comprehensive income (loss)	274	(849)	(7,037)
Net current period other comprehensive income (loss)	274	(849)	(11,316)
Accumulated other comprehensive income, balance	(13,099)	(13,373)	(12,524)
Net Unrealized Gains (Losses) on Investment Securities Available for Sale [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Accumulated other comprehensive income, balance	17,111	33,617	58,366
Other comprehensive income (loss) before reclassifications	(44,236)	7,566	20,987
Amounts reclassified from accumulated other comprehensive income (loss)	(1,811)	(24,072)	(45,736)
Net current period other comprehensive income (loss)	(46,047)	(16,506)	(24,749)
Accumulated other comprehensive income, balance	(28,936)	17,111	33,617
Post-retirement Unfunded Health Benefit [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward]
Accumulated other comprehensive income, balance	363	0	0
Other comprehensive income (loss) before reclassifications	519	395	0
Amounts reclassified from accumulated other comprehensive income (loss)	(105)	(32)	0
Net current period other comprehensive income (loss)	414	363	0
Accumulated other comprehensive income, balance	$ 777	$ 363	$ 0