Acquisitions - Goodwill (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Feb. 11, 2020	Sep. 30, 2019	Nov. 15, 2018	Sep. 30, 2018	Apr. 20, 2018	Apr. 06, 2018	Oct. 05, 2017
Goodwill
Goodwill	$ 501,536		$ 488,602		$ 255,876
Brooks Semiconductor Solutions Group
Goodwill
Goodwill	48,359		47,847		47,963
Brooks Life Sciences Products
Goodwill
Goodwill	103,278		101,957		104,212
Brooks Life Sciences Services
Goodwill
Goodwill	$ 349,899		$ 338,798		$ 103,701
RURO, Inc.
Goodwill
Goodwill		$ 11,116
Goodwill deductible for tax purposes		$ 0
GENEWIZ
Goodwill
Goodwill				$ 235,160
GENEWIZ | Brooks Life Sciences Services
Goodwill
Goodwill				235,200
Goodwill deductible for tax purposes				$ 0
Tec-Sem Group AG
Goodwill
Goodwill							$ 7,665
Goodwill deductible for tax purposes							0
Tec-Sem Group AG | Brooks Semiconductor Solutions Group
Goodwill
Goodwill							$ 7,700
4titude Limited
Goodwill
Goodwill								$ 38,185
Goodwill deductible for tax purposes								0
4titude Limited | Brooks Life Sciences Products
Goodwill
Goodwill								$ 38,185
BioSpeciMan Corporation
Goodwill
Goodwill						$ 2,700
Goodwill deductible for tax purposes						0
BioSpeciMan Corporation | Brooks Life Sciences Services
Goodwill
Goodwill						$ 2,700