Summary of Significant Accounting Policies - Foreign Currency Transactions (Details) - USD ($) $ in Thousands |
9 Months Ended | ||
---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
|
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Total stockholders’ equity | $ 410,951 | $ 352,850 | |
Retained earnings (accumulated deficit) | (1,334,141) | $ (1,063,610) | |
Net cash used in operating activities | (239,278) | $ (140,661) | |
Accounting Standards Update 2018-02 | |||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Retained earnings (accumulated deficit) | 383 | ||
Accounting Standards Update 2016-18 | |||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Net cash used in operating activities | $ 1,100 | ||
Accumulated Foreign Currency Adjustment Attributable | Accounting Standards Update 2018-02 | |||
New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
Total stockholders’ equity | $ (383) |