Summary of Significant Accounting Policies - Summarized Unaudited Financial Information for the Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Operating expenses	$ 85,128	$ 83,971
Operating loss	(31,381)	(40,533)
Other	3,418	(21,425)
Equity Method Investments
Schedule of Equity Method Investments [Line Items]
Current assets	75,902		$ 77,761
Non-current assets	12,016		11,040
Total assets	87,918		88,801
Current liabilities	14,095		11,588
Net assets	73,823		$ 77,213
Revenues	30	282
Operating expenses	13,343	17,660
Operating loss	(13,313)	(17,378)
Other	5	3
Net loss	$ (13,308)	$ (17,375)