Revenue from Contracts with Customers - Disaggregated By Reporting Unit (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenue	$ 220,227	$ 198,390	$ 430,727	$ 377,757
Automation Solutions
Disaggregation of Revenue [Line Items]
Total revenue	$ 68,733	72,445	$ 132,970	146,120
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember		brks:BrooksSemiconductorSolutionsGroupMember
Contamination Control Solutions
Disaggregation of Revenue [Line Items]
Total revenue	$ 45,463	30,047	$ 89,804	58,003
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember		brks:BrooksSemiconductorSolutionsGroupMember
Global Semiconductor Services
Disaggregation of Revenue [Line Items]
Total revenue	$ 10,727	10,385	$ 20,960	21,461
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember		brks:BrooksSemiconductorSolutionsGroupMember
Sample Management
Disaggregation of Revenue [Line Items]
Total revenue	$ 54,289	52,590	$ 106,007	102,892
Reporting unit, name of segment	brks:BrooksLifeSciencesMember		brks:BrooksLifeSciencesMember
GENEWIZ
Disaggregation of Revenue [Line Items]
Total revenue	$ 41,015	32,923	$ 80,986	49,281
Reporting unit, name of segment	brks:BrooksLifeSciencesMember		brks:BrooksLifeSciencesMember
Brooks Semiconductor Solutions Group
Disaggregation of Revenue [Line Items]
Total revenue	$ 124,923	112,877	$ 243,734	225,584
Brooks Life Sciences
Disaggregation of Revenue [Line Items]
Total revenue	$ 95,304	$ 85,513	$ 186,993	$ 152,173