Commitments and Contingencies - Additional Information (Detail) $ in Millions		1 Months Ended
	Feb. 22, 2019 USD ($)	May 31, 2019 USD ($)	Oct. 31, 2018 Suite	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($)
Manufacturing Agreement [Member] | Brammer [Member]
Commitments And Contingencies [Line Items]
Advance upfront fee to be paid on execution of amendment		$ 6.0
Quarterly capacity access fee payments		$ 13.3		$ 10.0
Cash payment under agreements					$ 55.0
Manufacturing Collaboration Agreement [Member] | Paragon [Member]
Commitments And Contingencies [Line Items]
Number of dedicated clean room suites | Suite			2
Number of additional clean room suites available on optional reserve | Suite			2
Agreement expiration date			Dec. 31, 2024
Manufacturing Supply Agreement [Member] | Paragon [Member]
Commitments And Contingencies [Line Items]
Pre-launch period purchase obligation, minimum amount per quarter per clean room	$ 4.0
Agreement expiration date	Dec. 31, 2024