Consolidated Statements Of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 74,496	$ 28,326	$ (153,366)
Available for sale securities:
Unrealized gains arising during the year	22,101	1,305	23,888
Reclassification adjustment for gains realized in net income (net of tax expense of $3,094, $930, and $3,431 in 2011, 2010, and 2009, respectively)	(4,641)	(1,396)	(5,147)
Income tax expense related to unrealized gains	(8,840)	(522)	(9,555)
Net change in unrealized gains	8,620	(613)	9,186
Held to maturity securities:
Reclassification adjustment for impairments realized in net income (net of tax benefit of $1,716 in 2009)			2,574
Amortization of unrealized losses on investment securities transferred to held to maturity (net of tax benefit of $70 in 2009)			103
Net change in unrealized losses on investment securities transferred to held to maturity			2,677
Unrealized (losses) gain related to factors other than credit (net of tax expense of $34 and $1,080 in 2011 and 2009, respectively and tax benefit of $150 in 2010)	(52)	225	(1,620)
Reclassification adjustment for impairments realized in net income (net of tax benefit of $108, $137 and $307 in 2011, 2010 and 2009, respectively)	161	205	460
Accretion of unrealized losses related to factors other than credit to investment securities held to maturity (net of tax benefit of $66, $115 and $120 in 2011, 2010 and 2009, respectively)	100	173	180
Net change in unrealized losses related to factors other than credit	209	603	(980)
Other comprehensive (loss) income, net of tax	8,829	(10)	10,883
Comprehensive income (loss)	$ 83,325	$ 28,316	$ (142,483)