Subsequent Events - Additional Information (Details) - Refinancing Agreement	Mar. 25, 2019 USD ($) d shares	Dec. 31, 2019 USD ($)	May 31, 2019 USD ($)
SVB and WestRiver | Tranche C | Scenario, Forecast
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity		$ 5,000,000
SVB and WestRiver | Tranche B | Scenario, Forecast
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity			$ 2,500,000
Subsequent Event | Silicon Valley Bank
Subsequent Event [Line Items]
Debt instrument, maturity date	Mar. 01, 2023
Interest rate, terms	the Company is to make interest-only payments through December 31, 2019 on Tranche A and Tranche B at a rate equal to the greater of the Prime Rate plus 1.00%, as defined in the 2019 Loan, or 6.5%, followed by an amortization period of 39 months of equal monthly payments of principal plus interest amounts until paid in full. The interest-only period will automatically be extended to June 30, 2020 if the Company achieves the Tranche C milestones, followed by an amortization period of 33 months of equal monthly payments of principal plus interest amounts until paid in full.
Percentage of final payment on principal amount of refinanced advances	6.00%
Subsequent Event | Silicon Valley Bank | Tranche A and Tranche B
Subsequent Event [Line Items]
Interest rate	6.50%
Amortization period of payments of principal plus interest amounts	39 months
Subsequent Event | Silicon Valley Bank | Tranche A and Tranche B | Prime Rate
Subsequent Event [Line Items]
Interest rate, percentage point added to reference rate	1.00%
Subsequent Event | Silicon Valley Bank | Tranche C
Subsequent Event [Line Items]
Amortization period of payments of principal plus interest amounts	33 months
Subsequent Event | Silicon Valley Bank | Tranche A
Subsequent Event [Line Items]
Proceeds from lines of credit	$ 7,500,000
Subsequent Event | SVB and WestRiver
Subsequent Event [Line Items]
Threshold trading days | d	10
Warrants expiration period	10 years
Line of credit facility, maximum borrowing capacity	$ 15,000,000
Subsequent Event | SVB and WestRiver | Tranche A
Subsequent Event [Line Items]
Number of warrants issued | shares	12,131
Line of credit facility, maximum borrowing capacity	$ 7,500,000
Subsequent Event | SVB and WestRiver | Tranche B
Subsequent Event [Line Items]
Number of warrants issued | shares	24,262