Summary of Significant Accounting Policies - Summarized Financial Data of Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract]
Operating expenses									$ 316,092	$ 320,469	$ 141,892
Operating loss	$ (32,590)	$ (28,821)	$ (23,222)	$ (40,533)	$ (34,395)	$ (7,916)	$ (17,430)	$ (87,123)	(125,166)	(146,864)	(69,962)
Other, net									(47,865)	68,830	(10,497)
Equity Method Investments
Equity Method Investment, Summarized Financial Information, Assets [Abstract]
Current assets	77,761				28,123				77,761	28,123
Non-current assets	11,040				1,539				11,040	1,539
Total assets	88,801				29,662				88,801	29,662
Equity Method Investment, Summarized Financial Information, Liabilities [Abstract]
Current liabilities	11,588				6,274				11,588	6,274
Net assets	$ 77,213				$ 23,388				77,213	23,388
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) [Abstract]
Revenues, net									417	1,176	940
Operating expenses									62,373	32,513	17,289
Operating loss									(61,956)	(31,337)	(16,349)
Other, net									1,535	(64)	35
Net loss									$ (60,421)	$ (31,401)	$ (16,314)