Commitments and Contingencies - Schedule of Future Minimum Payments under Manufacturing Agreement with Patheon (Detail) - Manufacturing and Supply Agreement with Patheon UK Limited [Member] $ in Thousands	Jun. 30, 2018 USD ($)
Property Subject To Or Available For Operating Lease [Line Items]
2018	$ 3,531
2019	8,308
2020	8,308
2021	8,308
2022	8,308
2023 and thereafter	24,924
Total	$ 61,687