Commitments and Contingencies - Additional Information (Detail)		3 Months Ended		6 Months Ended
	Jan. 08, 2016 USD ($) ft² Option	Mar. 31, 2016 USD ($) ft²	Mar. 31, 2015 USD ($)	Mar. 31, 2016 USD ($) ft²	Mar. 31, 2015 USD ($)
Other Commitments [Line Items]
Facility rent expense		$ 228,400	$ 191,000	$ 427,000	$ 362,000
Provision for recorded liabilities		0		0
Future commitments		49,000,000		49,000,000
Commitments expected to be incurred in fiscal 2016		17,000,000		17,000,000
Commitments expected to be incurred beyond fiscal 2016		$ 32,000,000		32,000,000
Corporate Headquarters In Pasadena
Other Commitments [Line Items]
Rental expense				$ 24,000
Operating lease expiration month and year				2019-09
Percentage of increase in annual rental cost				3.00%
Office space leases, in square feet | ft²		8,500		8,500
Research Facility in Madison
Other Commitments [Line Items]
Rental expense				$ 26,000
Office space leases, in square feet | ft²	60,000
Operating lease initial term	10 years
Operating lease commencement date	Jan. 01, 2016
Operating lease available for occupancy year				late 2016
Operating lease payments during initial term	$ 15,400,000
Estimated payment for real estate taxes, operating expenses and common area maintenance expenses	900,000
Estimated payments for leasehold improvements net of tenant improvement allowances	$ 7,300,000
Number of renewal options | Option	2
Operating leases renewal term	5 years
Other rental expenses including common area maintenance and real estate taxes				$ 20,000
Utilities costs per month				18,000
Monthly payments under capital lease				19,000
Total Monthly Facility Expense - Madison facility				83,000
Research Facility in Middleton
Other Commitments [Line Items]
Rental expense				$ 13,000
Operating lease expiration month and year				2016-12
Other rental expenses including common area maintenance and real estate taxes				$ 4,000