Intangible Assets - Summary of Acquired Intangible Assets Subject to Amortization (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Sep. 30, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 124,407	$ 95,775
Accumulated Amortization	41,044	35,532
Manufacturing Technologies, Core Products and Cell Lines [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	61,782	56,193
Accumulated Amortization	17,755	15,096
Tradenames, Licenses and Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	18,045	14,494
Accumulated Amortization	7,291	6,094
Customer Lists, Customer Relationships, and Supply Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	43,666	24,274
Accumulated Amortization	15,349	14,110
Government Grants [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	794	814
Accumulated Amortization	645	$ 232
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	120
Accumulated Amortization	$ 4