Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 12,685	$ 21,210	$ 23,737	$ 35,415
Other comprehensive income (loss):
Foreign currency translation adjustments	(832)	698	516	(2,764)
Unrealized gain (loss) on investments, net of tax	22	(38)	16	(33)
Interest rate swap fair value adjustment, net of tax	(667)	0	(2,899)	0
Other	0	(3)	0	(7)
Other comprehensive income (loss)	(1,477)	657	(2,367)	(2,804)
Comprehensive income	$ 11,208	$ 21,867	$ 21,370	$ 32,611