Restructuring Charges - General Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2017	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 975
Accrued restructuring costs		$ 1,127	$ 1,708
Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	975
Streamline Service Operations, Initiated Fiscal Year 2017 | Brooks Semiconductor Solutions Group | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Accrued restructuring costs		200
Reduce Global Footprint and Streamline Cost Structure, Initiated Fiscal Year 2016 | Brooks Semiconductor Solutions Group | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Accrued restructuring costs		$ 800
Integration of Contact Acquisition Initiated in Fiscal Year 2016 | Brooks Semiconductor Solutions Group | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	200
Streamlining Segment Structure, Integrating Acquisition, and Facility Closure, Initiated in Fiscal Year 2016 | Brooks Life Science Systems | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	100
Company-wide Action Initiated in Fiscal Year 2016 | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 700