Summary of Significant Accounting Policies and Select Balance Sheet Information - Schedule of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Less accumulated depreciation	$ (37,989)	$ (33,512)
Property and equipment, net	29,748	30,143
Land [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	4,415	4,420
Laboratory Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 25,467	22,024
Laboratory Fixtures and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	3 years
Laboratory Fixtures and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	10 years
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 24,513	21,717
Building and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	3 years
Building and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	20 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	10 years
Property and Equipment, Gross	$ 4,836	4,836
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 6,476	5,824
Office Furniture and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	3 years
Office Furniture and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life	10 years
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 2,030	$ 4,834