Debt - Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Long-term debt
Total long-term debt	$ 34,241	$ 23,718
Maturities of long-term debt
2021	8,875
2022	17,450
2023	11,889
Term loan
Long-term debt
Term loan payable	35,000	25,000
End of term fee	305
Unamortized debt issuance costs	(1,845)	(1,990)
Total long-term debt	33,460	23,010
Other long-term debt
Long-term debt
Total long-term debt	$ 781	$ 708