Restructuring Charges - General Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 82	$ 828	$ 131	$ 2,663
Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 82	$ 828	$ 131	2,663
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 Sciences | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges				300
Actions Initiated Prior to Fiscal Year 2016 | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 2,200