CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (143,011)	$ (2,136)	$ (151,576)	$ (9)
Other comprehensive income (loss):
Foreign currency translation adjustments	832	(943)	2,347	(199)
Change in unrealized gain (loss) on available for sale securities	131,213	(18,115)	56,511	(18,115)
Change in fair value of derivatives qualifying as cash flow hedges	(315)	(227)	1,033	214
Other comprehensive income (loss) before income tax benefit (expense)	131,730	(19,285)	59,891	(18,100)
Income tax benefit (expense) related to items in other comprehensive loss	124	89	(397)	(85)
Total other comprehensive income (loss)	131,854	(19,196)	59,494	(18,185)
Comprehensive loss	(11,157)	(21,332)	(92,082)	(18,194)
Less: Comprehensive loss (income) attributable to non-controlling interests	264	87	(189)	9
Comprehensive loss, net	$ (10,893)	$ (21,245)	$ (92,271)	$ (18,185)