Summary of Significant Accounting Policies - New accounting pronouncements (Details) - USD ($) $ in Thousands |
Jan. 01, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|---|
| New accounting pronouncements | |||
| Accumulated deficit | $ (231,630) | $ (161,492) | |
| ASU 2014-09 | Forecast | |||
| New accounting pronouncements | |||
| Accumulated deficit | $ (9,000) | ||
| Decrease in deferred revenue | $ (9,000) |
| X | ||||||||||
- Definition Amount of increase (decrease) in deferred revenue. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition The cumulative amount of the reporting entity's undistributed earnings or deficit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|