Collaborative Arrangement - Additional Information (Detail) - Abbott [Member] - USD ($)	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee received	$ 25,000,000
Collaborative arrangement milestone payment received	10,000,000
Collaboration revenue recognized	1,300,000	$ 2,400,000
Upfront and milestone fee payment included in deferred revenue	15,800,000		$ 17,100,000
Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement additional potential milestone payments receivable	$ 56,000,000