Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Non-cancelable operating sublease, expiration date for initial leased space			2024-12
Non-cancelable operating sublease, expiration date for expansion space leased			2022-12
Lessee, Operating Sublease, Existence of Option to Extend [true false]			true
Lessee, operating sublease, option to extend			options to extend for the entire premises through October 2028
Operating sublease, annual increase percentage for base rent			3.00%
Lessee, operating lease, discount rate	7.00%		7.00%
Weighted average remining lease term	4 years 6 months		4 years 6 months
Cash paid for operating lease liabilities	$ 0.7		$ 2.2
Rent expense		$ 0.6		$ 1.5