Fair Value Measurements - Contingent Purchase Price Consideration, Measured at Estimated Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Liabilities:
Warrant liability	$ 33	$ 52
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	3,000	7,027
Total assets measured and recorded at fair value	3,000	7,027
Liabilities:
Warrant liability	33	52
Contingent consideration	5,193	4,912
Total liabilities measured and recorded at fair value	5,226	4,964
Fair Value, Measurements, Recurring | Quoted Prices In     Active Markets (Level 1)
Assets:
Cash equivalents	3,000	7,027
Total assets measured and recorded at fair value	3,000	7,027
Liabilities:
Warrant liability	0	0
Contingent consideration	0	0
Total liabilities measured and recorded at fair value	0	0
Fair Value, Measurements, Recurring | Significant Other Observable  Inputs (Level 2)
Assets:
Cash equivalents	0	0
Total assets measured and recorded at fair value	0	0
Liabilities:
Warrant liability	0	0
Contingent consideration	0	0
Total liabilities measured and recorded at fair value	0	0
Fair Value, Measurements, Recurring | Unobservable  Inputs (Level 3)
Assets:
Cash equivalents	0	0
Total assets measured and recorded at fair value	0	0
Liabilities:
Warrant liability	33	52
Contingent consideration	5,193	4,912
Total liabilities measured and recorded at fair value	$ 5,226	$ 4,964