Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
NET INCOME	$ 6,355	$ 5,066
Other comprehensive income (loss), net of tax:
Change in net unrealized gains (losses) on available-for-sale securities, net of income taxes of ($33) and ($61)	(51)	(95)
Other comprehensive income (loss), net of tax	(51)	(95)
COMPREHENSIVE INCOME	$ 6,304	$ 4,971