Collaborative Arrangement - Additional Information (Detail) - Abbott [Member] - USD ($)	3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 30, 2020	Sep. 30, 2019	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2018
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee received				$ 45,800,000		$ 25,000,000
Collaborative arrangement milestone payment received	$ 10,800,000	$ 10,000,000.0
Collaboration revenue recognized	7,600,000		$ 2,000,000.0	10,400,000	$ 5,900,000
Upfront and milestone fee payment included in deferred revenue	17,500,000	$ 17,100,000		17,500,000
Collaboration revenue recognized included in balance at beginning of period				3,700,000	$ 5,900,000
Maximum [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement additional potential milestone payments receivable	$ 45,000,000			$ 45,000,000