Acquisitions - Goodwill (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Apr. 20, 2018	Apr. 06, 2018	Oct. 05, 2017	Sep. 30, 2017
Goodwill
Goodwill	$ 282,205				$ 233,638
Brooks Semiconductor Solutions Group
Goodwill
Goodwill	74,213				66,818
Brooks Life Sciences
Goodwill
Goodwill	$ 207,992				$ 166,820
BioSpeciMan Corporation
Goodwill
Goodwill		$ 2,700
Goodwill deductible for tax purposes		0
BioSpeciMan Corporation | Brooks Life Sciences
Goodwill
Goodwill		$ 2,700
Tec-Sem Group AG
Goodwill
Goodwill			$ 7,573
Goodwill deductible for tax purposes			0
Tec-Sem Group AG | Brooks Semiconductor Solutions Group
Goodwill
Goodwill			$ 7,600
4titude Limited
Goodwill
Goodwill				$ 38,185
Goodwill deductible for tax purposes				0
4titude Limited | Brooks Life Sciences
Goodwill
Goodwill				$ 38,185