Condensed Consolidated Statements of Comprehensive Income (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net income	$ 6,052	$ 63,388	$ 9,190	$ 69,195
Available for sale securities
Unrealized gain (loss) arising during period	1,759	(2,463)	4,009	(1,489)
Change in unrealized losses for which a portion of other than temporary impairment has been recognized in earnings	219	258	338	291
Reclassification adjustment for other than temporary impairment included in earnings	0	26	0	26
Reclassification adjustments for gains included in earnings	(2)	(15)	(2)	(8)
Unrealized gains (losses) recognized in other comprehensive income on available for sale securities	1,976	(2,194)	4,345	(1,180)
Income tax expense (benefit)	691	(413)	1,521	(413)
Unrealized gains (losses) recognized in other comprehensive income on available for sale securities, net of tax	1,285	(1,781)	2,824	(767)
Derivative instruments
Unrealized loss arising during period	0	(35)	0	(38)
Reclassification adjustment for expense recognized in earnings	0	114	0	208
Reclassification adjustment for accretion on settled derivatives	95	0	190	0
Unrealized gains recognized in other comprehensive income on derivative instruments	95	79	190	170
Income tax expense (benefit)	34	(1,385)	67	(1,385)
Unrealized gains recognized in other comprehensive income on derivative instruments, net of tax	61	1,464	123	1,555
Other comprehensive income (loss)	1,346	(317)	2,947	788
Comprehensive income	$ 7,398	$ 63,071	$ 12,137	$ 69,983