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, 2017	Sep. 30, 2016
Property, Plant and Equipment [Line Items]
Less accumulated depreciation	$ (29,927)	$ (26,979)
Property and equipment, net	22,942	19,601
Land [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	4,420	4,359
Laboratory Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 19,491	15,243
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	$ 21,924	19,589
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
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and Equipment, Gross	$ 4,541	3,948
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	$ 2,493	$ 3,441