Commitments and Contingencies - Additional Information (Detail)	9 Months Ended
	Jun. 30, 2017
California [Member]
Loss Contingencies [Line Items]
Lease expiration date	Jun. 30, 2021
Extension period available after expiration of lease	5 years
North Carolina [Member]
Loss Contingencies [Line Items]
Lease expiration date	Nov. 30, 2015
Lease renewal period	3 months
Massachusetts [Member]
Loss Contingencies [Line Items]
Lease expiration date	Nov. 30, 2015
Lease renewal period	1 year