Condensed Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 32,499	$ 108,696	$ 94,205	$ 133,365
Other comprehensive income (loss):
Net unrealized loss on available-for- sale securities, net of tax	(5)	(237)	(179)	(278)
Other comprehensive loss	(5)	(237)	(179)	(278)
Comprehensive income	$ 32,494	$ 108,459	$ 94,026	$ 133,087