Condensed Consolidated Statements of Comprehensive Income (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net income	$ 63,388	$ 4,333	$ 69,195	$ 7,837
Available for sale securities
Unrealized gain (loss) arising during period	(2,463)	2,671	(1,489)	1,634
Change in unrealized losses for which a portion of other than temporary impairment has been recognized in earnings	258	204	291	333
Reclassification adjustment for other than temporary impairment included in earnings	26	85	26	262
Reclassification adjustments for (gains) losses included in earnings	(15)	(151)	(8)	(843)
Unrealized gains (losses) recognized in other comprehensive income on available for sale securities	(2,194)	2,809	(1,180)	1,386
Income tax benefit	(413)	0	(413)	0
Unrealized gains (losses) recognized in other comprehensive income on available for sale securities, net of tax	(1,781)	2,809	(767)	1,386
Derivative instruments
Unrealized loss arising during period	(35)	(24)	(38)	(75)
Reclassification adjustment for expense recognized in earnings	114	120	208	305
Reclassification adjustment for accretion on settled derivatives	0	146	0	291
Unrealized gains recognized in other comprehensive income on derivative instruments	79	242	170	521
Income tax benefit	(1,385)	0	(1,385)	0
Unrealized gains recognized in other comprehensive income on derivative instruments, net of tax	1,464	242	1,555	521
Other comprehensive income (loss)	(317)	3,051	788	1,907
Comprehensive income	$ 63,071	$ 7,384	$ 69,983	$ 9,744