Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Rollforward (Details)

v3.19.2
Fair Value Measurements - Rollforward (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Change in fair value $ 1,436 $ 278 $ 1,725 $ (109)
Fair value, measurements, recurring        
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at December 31, 2018     2,798  
Balance at March 31, 2019 4,523   4,523  
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)        
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Balance at December 31, 2018     2,798  
Change in fair value     1,725  
Balance at March 31, 2019 $ 4,523   $ 4,523