Restructuring Charges - General Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 49	$ 860	$ 49	$ 1,835
Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 49	860	$ 49	1,835
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		1,200		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		200
Company-wide Action Initiated in Fiscal Year 2016 | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges, adjustment		$ 500
Actions Initiated Prior to Fiscal Year 2016 | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 1,400