CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 150,184	$ 23,117	$ 442,658	$ 294,162	$ 419,222
Other comprehensive loss:
Foreign currency translation	(6,421)	(11,239)	(39,804)	(7,718)
Change in unrealized gain on marketable securities	(92)	0	158	(5,046)
Other	1,094	467	(2,403)	(949)
Total other comprehensive loss	(5,419)	(10,772)	(42,049)	(13,713)	$ (20,686)
Comprehensive income	144,765	12,345	400,609	280,449
Comprehensive income attributable to noncontrolling interest	732	265	1,064	1,047
Comprehensive income attributable to common stockholders	$ 144,033	$ 12,080	$ 399,545	$ 279,402