Summary of Significant Accounting Policies - Schedule of Manufacturing and Other Contingent Milestone and Co-Development Payments (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Total manufacturing and other commitments	$ 11,412
Molgradex API Manufacturer [Member]
Summary Of Significant Accounting Policies [Line Items]
Delivery of working and master cell banks	600
Achievement of certain milestones related to regulatory approval of Molgradex	2,000
Molgradex Nebulizer Manufacturer [Member]
Summary Of Significant Accounting Policies [Line Items]
Achievement of various development activities and regulatory approval of nebulizer utilized to administer Molgradex	8,062
Molgradex (aPAP) Japanese Licensee [Member] | Japan [Member]
Summary Of Significant Accounting Policies [Line Items]
Co-development and regulatory costs	$ 750