Collaborations and Licensing Arrangements - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended			12 Months Ended
	Mar. 29, 2019	May 31, 2018	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Oct. 31, 2018	Sep. 30, 2018
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue — current			$ 30,840,000				$ 32,503,000
Revenue — collaborations and services			16,235,000		$ 17,448,000
Deferred revenue — long term			1,772,000				$ 8,344,000
AFREZZA product sales
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue — collaborations and services			8,000,000		$ 5,076,000
Collaboration and License Agreement | Receptor CLA
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue — current			200,000
Collaboration and License Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received								$ 45,000,000
Milestone Payment Received	$ 12,500,000
Total transaction price			101,400,000
Deferred revenue			30,400,000
Collaboration and License Agreement | United Therapeutics Corporation | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential milestone payments to be receive			25,000,000
Additional option exercise and development milestone payments to be receive			40,000,000
Research Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received									$ 10,000,000
Total transaction price			10,000,000
Deferred revenue — current			100,000
Research Agreement | United Therapeutics Corporation | Product Prototype
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total transaction price			$ 9,000,000
Revenue performance obligation, method used			The revenue for the product prototype is recognized using an output method (based on project milestones achieved and surveys of performance completed to date). The Company believes that this method best reflects the measure of progress toward complete satisfaction of the performance obligation.
Research Agreement | United Therapeutics Corporation | Engineering Consulting Services
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total transaction price			$ 1,000,000
Revenue performance obligation, method used			The revenue for the engineering consulting services was recognized using a ratable method until the obligation was satisfied. The Company believes that this method best reflects the measure of progress toward complete satisfaction of the performance obligation.
Research Agreement | United Therapeutics Corporation | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Potential milestone payments to be receive				$ 30,000,000
Supply and Distribution Agreement | AFREZZA product sales | Biomm
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue — collaborations and services				$ 700,000
License and Distribution Agreement | Foreign Country | India Tax Authority
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Income Taxes Paid						$ 200,000
License and Distribution Agreement | Cipla Distribution Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			$ 1,900,000
Deferred revenue — current			100,000
Marketing and distribution agreement date		2018-05
Deferred revenue — long term			$ 1,800