Fair Value Measurement - Assets and Liabilities at Fair Value (Details) - Contingent consideration - USD ($)
$ in Thousands
Mar. 31, 2020
Dec. 31, 2019
Liabilities:    
Contingent consideration due to seller $ (1,700) $ (1,700)
Fair Value, Measurements, Recurring    
Liabilities:    
Contingent consideration due to seller (1,737) (1,707)
Fair Value, Measurements, Recurring | Level 1    
Liabilities:    
Contingent consideration due to seller 0 0
Fair Value, Measurements, Recurring | Level 2    
Liabilities:    
Contingent consideration due to seller 0 0
Fair Value, Measurements, Recurring | Level 3    
Liabilities:    
Contingent consideration due to seller $ (1,737) $ (1,707)