Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 21,878	$ (229,858)	$ (553,577)	$ (568,266)
Other comprehensive income (loss):
Unrealized net gain on derivatives and short-term marketable securities, net of tax	3,349	11	48,359	219
Reclassification adjustment for net gains included in net income (loss)	(14,246)		(15,523)
Foreign currency translation adjustment	2,014	(9,192)	(3,970)	(24,182)
Other comprehensive income (loss)	(8,883)	(9,181)	28,866	(23,963)
Comprehensive income (loss)	$ 12,995	$ (239,039)	$ (524,711)	$ (592,229)