Debt - Summary (Details) - Loan Agreement - Term loan $ in Millions		1 Months Ended		12 Months Ended
	Mar. 11, 2020 USD ($)	Feb. 29, 2020 USD ($)	Dec. 31, 2018 USD ($) item	Dec. 31, 2019 USD ($)
Debt
Maximum borrowing capacity			$ 75.0
Number of additional term loan advances | item			5
Interest rate (as a percent)				9.80%
Fee due at maturity, as a percentage of aggregate advances				6.95%
The amount in excess of which prepayments may be made				$ 5.0
Minimum cash and cash equivalents in accounts to be maintained				10.0
Maximum value of lender option to purchase equity securities				2.0
Loan origination costs				1.3
Initial fee paid to lender				$ 0.7
Prime rate
Debt
Variable rate basis				interest minus 5.50%
Variable interest rate margin (as a percent)				9.80%
Variable rate adjustment (as a percent)				(5.50%)
Initial Advance
Debt
Principal amount of advances outstanding			$ 25.0
Tranche 2 Advance
Debt
Maximum borrowing capacity			10.0
Tranche 3 Advance
Debt
Maximum borrowing capacity			5.0
Tranche 4 Advance
Debt
Maximum borrowing capacity			10.0
Tranche 5 Advance
Debt
Maximum borrowing capacity			15.0
Tranche 6 Advance
Debt
Maximum borrowing capacity			5.0
Tranche 7 Advance
Debt
Maximum borrowing capacity			$ 5.0
Prepayment during the first 12 months following initial closing
Debt
Prepayment penalty as a percentage of the amount being repaid				3.00%
Prepayment after the first 12 months following initial closing but before 24 months
Debt
Prepayment penalty as a percentage of the amount being repaid				2.00%
Prepayment after the first 24 months following initial closing but before maturity
Debt
Prepayment penalty as a percentage of the amount being repaid				1.00%
Subsequent Event
Debt
Principal amount of advances outstanding	$ 35.0
Percent of net product revenue sales target	70.00%	80.00%
Minimum liquidity requirement		$ 40.0
Subsequent Event | Tranche 7 Advance
Debt
Maximum borrowing capacity	$ 5.0