Notes Payable - Additional Information (Details) - Credit Agreement $ in Thousands	1 Months Ended	6 Months Ended
	Dec. 31, 2018 USD ($) installment	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Notes Payable
Borrowing capacity under the agreement		$ 25,000
Borrowings outstanding	$ 25,000	25,000	$ 25,000
Repayments of debt, Principal		25,000
Number of equal monthly installments | installment	36
Final payment due (as a percent)	3.50%
Additional final payment	$ 875	875
2021
Notes Payable
Repayments of debt, Principal		$ 8,333
Required monthly principal payment	694
Achievement of certain milestones
Notes Payable
Repayments of debt, Principal	$ 1,042
Number of equal monthly installments | installment	24
LIBOR
Notes Payable
Borrowings outstanding	$ 25,000
Effective annual interest rate (as a percent)	9.76%
Interest rate floor (as a percent)	2.00%
Basis spread (as a percent)	7.25%