CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (11,214)	$ 21,937	$ 59,505	$ 252,076
Other comprehensive income (loss):
Unrealized gain (loss) on available for sale securities, net of tax	88	(312)	172	(175)
Cumulative translation adjustment, net of tax	18	(595)	(632)	(1,651)
Comprehensive (loss) income	$ (11,108)	$ 21,030	$ 59,045	$ 250,250