Fair Value Measurements - Contingent Consideration Payable (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
|
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Change in fair value of contingent consideration | $ (13,500) | $ 7,500 | ||
Contingent consideration payable | ||||
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] | ||||
Balance, beginning of period | $ 14,664 | $ 21,911 | 17,358 | 8,634 |
Issuance | 0 | 0 | 0 | 18,000 |
Payments of contingent consideration | (1,162) | (1,184) | (3,856) | (1,907) |
Purchase accounting adjustment | 0 | 0 | 0 | 3,500 |
Change in fair value of contingent consideration | 0 | 0 | 0 | (7,500) |
Balance, end of period | $ 13,502 | $ 20,727 | $ 13,502 | $ 20,727 |