Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
Jan. 01, 2019 |
Mar. 31, 2018 |
Jun. 30, 2019 |
|
| Recent Accounting Pronouncements | |||
| Cumulative effect of adoption of ASU | $ 1,818 | ||
| Restricted Cash | $ 71,917 | ||
| Future minimum cash commitments under operating leases | $ 17,000 | ||
| ASU 2018-02 | |||
| Recent Accounting Pronouncements | |||
| Cumulative effect of adoption of ASU | $ 100 |