Credit Facility and Term Loans - Additional Information (Details) - USD ($)			12 Months Ended
	Nov. 23, 2018	Oct. 16, 2017	Dec. 31, 2019	Dec. 31, 2018	Sep. 04, 2018
Debt Instrument [Line Items]
Available balance of credit facility			$ 0
Interest expense of credit facilities			2,500,000	$ 1,200,000
Debt issuance costs			700,000	400,000
Repaying of term loan				6,776,000
Interest expense			4,532,000	2,354,000
Warrants to purchase shares, exercise price					$ 15.60
Outstanding borrowings from lenders			$ 35,100,000
Term Loan
Debt Instrument [Line Items]
Debt instrument maturity month and year		2020-10
Term Loan | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		9.75%
Horizon Loan Agreement
Debt Instrument [Line Items]
Credit facility maximum borrowing amount				$ 15,000,000
Debt instrument maturity month and year				2023-01
Debt issuance costs				$ 1,000,000
Warrants to purchase shares, exercise price			$ 15.60
Warrants term				10 years
Fair value on issuance				$ 900,000
Debt discount				$ 900,000
Horizon Loan Agreement | Common Stock
Debt Instrument [Line Items]
Warrants to purchase shares				76,923
Warrants to purchase shares, exercise price				$ 15.60
Horizon Loan Agreement | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate				9.90%
Description of variable rate basis				one-month LIBOR
Horizon Loan Agreement | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Potential additional interest				2.50%
Horizon Term Loan
Debt Instrument [Line Items]
Debt issuance costs			$ 300,000	$ 500,000
Debt issuance costs			836,000	1,022,000
Interest expense			2,000,000	0
Outstanding borrowings from lenders			15,000,000
Mid Cap Prior Term Loan
Debt Instrument [Line Items]
Term loan, borrowing		$ 7,000,000
Repaying of term loan				4,900,000
Prepayment penalty				100,000
Mid Cap Prior Term Loan | Maximum
Debt Instrument [Line Items]
Debt issuance costs			100,000	100,000
Amortization of debt issuance costs				200,000
Interest expense				$ 800,000
Mid Cap Prior Credit Facility
Debt Instrument [Line Items]
Credit facility maximum borrowing amount		15,000,000
Mid Cap Credit Facility
Debt Instrument [Line Items]
Credit facility maximum borrowing amount	$ 25,000,000
Additional increase in borrowing amount	$ 50,000,000	$ 30,000,000
Line of credit facility, unused capacity, commitment fee percentage	0.50%
Line of credit facility, minimum liquidity financial covenant requirement in cash on hand	$ 5,000,000
Debt offset against and expense over the term				3 years
Debt issuance costs				$ 1,300,000
Unamortized debt issuance costs				700,000
Line of credit, outstanding			23,000,000	16,500,000
Available balance of credit facility			$ 0	1,400,000
Mid Cap Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	5.75%
New Credit Facility and Term Loan
Debt Instrument [Line Items]
Line of credit facility covenant minimum liquidity requirement in unrestricted cash				$ 5,000,000