CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 9,564	$ 13,173
Other comprehensive income:
Unrealized gain (loss) on available-for-sale securities, net of tax	(3)	16
Comprehensive income	$ 9,561	$ 13,189