Acquisitions - Purchase Consideration (Details) $ in Thousands								3 Months Ended	12 Months Ended
	Nov. 15, 2018 USD ($) customer	Apr. 20, 2018 USD ($)	Apr. 06, 2018 USD ($)	Oct. 05, 2017 USD ($)	Aug. 22, 2017 USD ($)	Jul. 05, 2017 USD ($)	Nov. 28, 2016 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Business Acquisition [Line Items]
Non-cash consideration transferred											$ 10,348
Net cash outflow									$ 442,704	$ 85,755	$ 44,791
GENEWIZ
Business Acquisition [Line Items]
Total purchase price	$ 442,700
Change in purchase price								$ (4,000)
Working capital adjustment	$ 400
GENEWIZ | Minimum
Business Acquisition [Line Items]
Number of institutional customers | customer	4,000
Tec-Sem Group AG
Business Acquisition [Line Items]
Cash payment net of cash acquired and subject to working capital adjustments			$ 15,600
4titude Limited
Business Acquisition [Line Items]
Total purchase price				$ 65,100
Cash payment net of cash acquired and subject to working capital adjustments				64,800
Liabilities incurred				$ 400
BioSpeciMan Corporation
Business Acquisition [Line Items]
Total purchase price		$ 5,200
Cash payment net of cash acquired and subject to working capital adjustments		$ 5,200
PBMMI and Novare
Business Acquisition [Line Items]
Total purchase price						$ 34,300
Cash payment net of cash acquired and subject to working capital adjustments						$ 34,300
Cool Lab, LLC
Business Acquisition [Line Items]
Total purchase price							$ 15,200
Cash payment							4,800
Liabilities incurred							100
Non-cash consideration transferred							10,300
Liabilities arising from contingencies, amount recognized							700		$ 0	$ 800
Equity method investments, fair value disclosure							$ 3,100
RURO, Inc.
Business Acquisition [Line Items]
Total purchase price					$ 5,500
Cash payment					5,200
Liabilities incurred					$ 400