Leasing - Components of Lease Expense (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended |
|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2019 |
|
| Leases [Abstract] | ||
| Operating lease cost | $ 1,173 | $ 2,315 |
| Variable lease cost | 94 | 190 |
| Short-term lease cost | 1 | 1 |
| Sublease income | (9) | (17) |
| Total lease cost | $ 1,259 | $ 2,489 |