Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 95,401	$ 81,241	$ 110,945
Other comprehensive income (loss):
Foreign currency translation adjustments	(3,391)	(1,598)	591
Unrealized gain (loss) on investments, net of tax	(31)	1,369	418
Other	(119)	(152)	433
Other comprehensive income (loss)	(3,541)	(381)	1,442
Comprehensive income	$ 91,860	$ 80,860	$ 112,387