Revenue - Disaggregated By Reporting Unit (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenue	$ 179,368	$ 142,599
Automation Solutions
Disaggregation of Revenue [Line Items]
Total revenue	$ 73,675
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember
Contamination Control Solutions
Disaggregation of Revenue [Line Items]
Total revenue	$ 27,956
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember
Global Semiconductor Services
Disaggregation of Revenue [Line Items]
Total revenue	$ 11,076
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember
Sample Management
Disaggregation of Revenue [Line Items]
Total revenue	$ 50,303
Reporting unit, name of segment	brks:BrooksLifeSciencesMember
GENEWIZ
Disaggregation of Revenue [Line Items]
Total revenue	$ 16,358
Reporting unit, name of segment	brks:BrooksLifeSciencesMember
Brooks Semiconductor Solutions Group
Disaggregation of Revenue [Line Items]
Total revenue	$ 112,707	95,157
Brooks Life Sciences
Disaggregation of Revenue [Line Items]
Total revenue	$ 66,661	$ 47,442