Revenue from Contracts with Customers - Disaggregated By Reporting Unit (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 198,390	$ 179,368	$ 156,952	$ 377,757	$ 299,551
Automation Solutions
Disaggregation of Revenue [Line Items]
Total revenue	$ 72,445			$ 146,120
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember			brks:BrooksSemiconductorSolutionsGroupMember
Contamination Control Solutions
Disaggregation of Revenue [Line Items]
Total revenue	$ 30,047			$ 58,003
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember			brks:BrooksSemiconductorSolutionsGroupMember
Global Semiconductor Services
Disaggregation of Revenue [Line Items]
Total revenue	$ 10,385			$ 21,461
Reporting unit, name of segment	brks:BrooksSemiconductorSolutionsGroupMember			brks:BrooksSemiconductorSolutionsGroupMember
Sample Management
Disaggregation of Revenue [Line Items]
Total revenue	$ 52,590			$ 102,892
Reporting unit, name of segment	brks:BrooksLifeSciencesMember			brks:BrooksLifeSciencesMember
GENEWIZ
Disaggregation of Revenue [Line Items]
Total revenue	$ 32,923			$ 49,281
Reporting unit, name of segment	brks:BrooksLifeSciencesMember			brks:BrooksLifeSciencesMember
Brooks Semiconductor Solutions Group
Disaggregation of Revenue [Line Items]
Total revenue	$ 112,877		108,413	$ 225,584	203,570
Brooks Life Sciences
Disaggregation of Revenue [Line Items]
Total revenue	$ 85,513	$ 66,661	$ 48,539	$ 152,173	$ 95,981