Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 453,555	$ 337,610
Other comprehensive income (loss):
Unrecognized gain (loss) on equity investments		0	(10,569)
Foreign currency translation gain (loss)		16,326	5,713
Total other comprehensive income (loss)		16,326	(4,856)
Total comprehensive income (loss), total		469,881	332,754
Total comprehensive income (loss) attributable to noncontrolling interests	[1]	322	3,636
Comprehensive income (loss) attributable to controlling interests		$ 469,559	$ 329,118

[1] Includes amounts attributable to redeemable noncontrolling interests.