Condensed 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
Statement of Income and Comprehensive Income [Abstract]
Net Income (Loss)	$ 19,444	$ (19,048)	$ 54,758	$ 3,123
Other Comprehensive Income, Net of Tax
Unrealized gains on available-for-sale securities	8,733	25,498	31,965	64,680
Reclassification adjustment for gains included in net income	0	(813)	0	(346)
Net unrealized gains on securities	8,733	24,685	31,965	64,334
Tax effect	(3,398)	(9,674)	(12,435)	(25,212)
Net of tax amount	5,335	15,011	19,530	39,122
Unrealized losses on derivatives used for cash flow hedges	(2,507)	0	(8,446)	0
Tax effect	975	0	3,285	0
Net of tax amount	(1,532)	0	(5,161)	0
Total other comprehensive income, net of tax	3,803	15,011	14,369	39,122
Total Comprehensive Income (Loss)	$ 23,247	$ (4,037)	$ 69,127	$ 42,245