Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 11,051	$ 5,246
Other comprehensive income (loss), before tax expense (benefit):
Unrealized holding gains (losses) on securities arising during the period	99	(1,616)
Non-credit related gains on securities not expected to be sold	1,498	1,869
Less: reclassification adjustment for losses on securities included in net income	0	(577)
Total other comprehensive income (loss), before tax expense (benefit)	1,597	(324)
Income tax expense (benefit) related to items of other comprehensive income (loss)	558	(113)
Comprehensive Income	$ 12,090	$ 5,035