Significant Accounting Policies - Accounting Pronouncements Adopted in the Year (Details) - USD ($) $ in Thousands |
Dec. 31, 2019 |
Jan. 01, 2019 |
Dec. 31, 2018 |
|---|---|---|---|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
| Right-of-use assets | $ 134,774 | ||
| Lease liabilities | 151,707 | ||
| Adjustment to reduce opening accumulated deficit | $ (304,224) | $ (187,757) | |
| Topic 842 | |||
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] | |||
| Right-of-use assets | $ 91,140 | ||
| Lease liabilities | 103,310 | ||
| Adjustment to reduce opening accumulated deficit | $ 8,375 |