Convertible Senior Notes - Schedule of Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||||
|---|---|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Jun. 30, 2017 |
Nov. 30, 2013 |
|
| Debt Instrument [Line Items] | |||||
| Proceeds | $ 0 | $ 0 | $ 54,071 | ||
| 2022 Warrants | |||||
| Debt Instrument [Line Items] | |||||
| Proceeds | $ 54,071 | ||||
| Shares (in shares) | 5,807,000 | ||||
| Strike Price (in USD per share) | $ 203.40 | ||||
| Shares as of December 31, 2019 (in shares) | 5,807,000 | ||||
| 2018 Warrants | |||||
| Debt Instrument [Line Items] | |||||
| Proceeds | $ 84,525 | ||||
| Shares (in shares) | 7,783,000 | ||||
| Strike Price (in USD per share) | $ 107.46 | ||||
| Shares as of December 31, 2019 (in shares) | 0 | ||||