Restructuring and Other Charges Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 7,300
Restructuring reserve	7,389	$ 1,654	$ 3,297	$ 7,389	$ 3,297	$ 2,073	$ 3,928	$ 3,475
Expenses	7,336		685	8,811	3,353
Facilities and other contract termination costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	200
Restructuring reserve	96	0	904	96	904	433	1,175	71
Expenses	160		0	25	1,205
Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	7,200			8,800
Restructuring reserve	7,293	1,654	2,393	7,293	2,393	$ 1,640	$ 2,753	$ 3,404
Expenses	7,176		685	8,786	2,148
Brooks Product Solutions | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring cost incurred to date		1,900	$ 5,000		$ 5,000
Actions Initiated in Current Period
Restructuring Cost and Reserve [Line Items]
Restructuring charges	5,200
Actions Initiated in Current Period | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	5,200			5,200
Restructuring expected cost remaining	500			500
Expected restructuring charges	5,700			5,700
Actions Initiated in Prior Periods
Restructuring Cost and Reserve [Line Items]
Restructuring charges		2,100
Actions Initiated in Prior Periods | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring cost incurred to date		3,600
Actions Initiated in Prior Periods | Brooks Product Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring charges	400
Actions Initiated in Prior Periods | Brooks Product Solutions | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	400			1,200
Restructuring cost incurred to date		4,600
Expected restructuring charges	5,000			5,000
Actions Initiated in Prior Periods | Brooks Life Science Systems
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,600
Actions Initiated in Prior Periods | Brooks Life Science Systems | Workforce-related termination benefits
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,600			2,400
Restructuring cost incurred to date		$ 800
Expected restructuring charges	$ 2,400			$ 2,400