Collaborative Arrangement - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue	$ 23,873,000		$ 26,883,000	$ 81,165,000	$ 72,321,000
Abbott Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement payment received				60,800,000
Total revenue	1,000,000.0		7,600,000	14,800,000	10,400,000
Collaboration revenue recognized included in balance at beginning of period				3,800,000	$ 3,700,000
Upfront and milestone fee payment included in deferred revenue	16,100,000			16,100,000				$ 15,900,000
Abbott Agreement [Member] | Upfront Payment [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement payment received							$ 25,000,000
Abbott Agreement [Member] | Milestone Payment [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement payment received		$ 15,000,000	$ 10,800,000			$ 10,000,000
Abbott Agreement [Member] | Maximum [Member] | PMA Milestone [Member] | TRANSCEND Clinical Trial [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaborative arrangement additional potential milestone payments receivable	$ 30,000,000			$ 30,000,000