Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 100,725	$ 122,216	$ 410,516	$ 355,105
Other comprehensive income:
Change in unrealized loss on marketable securities		153		(1,466)
Change in unrealized loss on interest rate swaps	(72)	103	344	308
Change in foreign currency translation adjustments		(8,056)		(6,335)
Net current-period other comprehensive income	(72)	(7,800)	344	(7,493)
Comprehensive income	100,653	114,416	410,860	347,612
Comprehensive income attributable to noncontrolling interests	(567)	(1,186)	(882)	(13,926)
Comprehensive income attributable to the Company	$ 100,086	$ 113,230	$ 409,978	$ 333,686