Commitments and Contingencies - Series A Convertible Redeemable Preferred Stock Offering (Details) $ in Thousands			1 Months Ended	3 Months Ended	6 Months Ended
	Dec. 20, 2016 USD ($) shares	Dec. 04, 2016 USD ($) investor shares	Jan. 31, 2017 USD ($) shares	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Series A Convertible Redeemable Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Total redeemable noncontrolling interests and equity				$ 232,030	$ 232,030	$ 332,957
Series A Convertible Redeemable Preferred Stock | Additional paid-in capital
Subsidiary, Sale of Stock [Line Items]
Accretion to redemption value					$ 101,194
Series A Redeemable Convertible Preferred Stock - Beneficial Conversion Feature | Additional paid-in capital
Subsidiary, Sale of Stock [Line Items]
Beneficial conversion feature of preferred stock				$ 261,794
Accretion period					1 year
Private Placement
Subsidiary, Sale of Stock [Line Items]
Number of investors (investor) | investor		6
Net proceeds from sale of stock	$ 328,000	$ 383,000	$ 55,000
Sale of stock, number of shares issued in transaction (in shares) | shares	343,000		57,000
Sale of stock, amount financed			$ 57,000
Sale of stock redemption period		5 years
Private Placement | Series A Convertible Redeemable Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares agreed to be issued in transaction (in shares) | shares		400,000
Private Placement | Series A-1 Redeemable Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares agreed to be issued in transaction (in shares) | shares		23,000
Private Placement | Series A-2 Redeemable Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares agreed to be issued in transaction (in shares) | shares		377,000