Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net income	$ 10,040	$ 6,185
Other comprehensive income, net of tax:
Unrealized gain (loss) on investment securities arising during the period, net of tax	(1,822)	1,796
Less reclassification adjustment for realized gain on sale of securities included in net income, net of tax	(417)	(654)
Total other comprehensive income (loss)	(2,239)	1,142
Total comprehensive income	$ 7,801	$ 7,327