Summary of Significant Accounting Policies - Schedule of Manufacturing and Other Contingent Milestone and Co-Development Payments (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Total manufacturing and other commitments	$ 12,535
Active Pharmaceutical Ingredients [Member]
Summary Of Significant Accounting Policies [Line Items]
Achievement of certain milestones related to validation of API and regulatory approval of Molgradex	3,650
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	7,635
Molgradex Japanese Licensee [Member] | Japan [Member]
Summary Of Significant Accounting Policies [Line Items]
Co-development and regulatory costs	750
NTM [Member]
Summary Of Significant Accounting Policies [Line Items]
First commercial sale in the U.S. of Molgradex in treatment of NTM	$ 500