Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Consolidated Statements of Comprehensive Income [Abstract]
Net Income (Loss)	$ 20,991	$ 32,944	$ 349,028	$ (11,577)
Other comprehensive income
Unrealized gain on securities available for sale	10,887	2,817	13,944	15,120
Reclassification adjustment for net (gain) loss on securities included in net income		(3)		1,373
Unrealized gain on securities transferred from available for sale to held to maturity				18,510
Amortization of unrealized gain on securities transferred to held to maturity	(1,715)	(1,675)	(5,571)	(1,887)
Unrealized loss on qualifying cash flow hedges, net of change and reclassifications	(2,065)	(1,428)	(8,110)	(3,816)
Other comprehensive income (loss), before income taxes	7,107	(289)	263	29,300
Income tax provision (benefit) related to other comprehensive income items	2,488	(137)	92	10,219
Other comprehensive income (loss)	4,619	(152)	171	19,081
Comprehensive income	$ 25,610	$ 32,792	$ 349,199	$ 7,504