Revised Consolidated Statement of Operations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended							6 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Mar. 31, 2012	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Schedule of Condensed Consolidating Statement of Operations [Line Items]
Equity in earnings of joint ventures	$ 196	$ 430	$ 1,050	$ 1,758	$ 1,632	$ 646	$ 779	$ 1,480	$ 1,425	$ 1,676	$ 3,057	$ 4,815	$ 1,074	$ 33
Net income (loss)	8,025	9,726	2,831	12,720	66,921	26,841	23,955	12,557	50,796	20,582	117,717	130,437	59,884	(227,527)
Net income (loss) attributable to Brooks Automation, Inc.	8,028	9,721	2,823	12,692	66,915	26,823	23,955	12,544	50,778	20,572	117,693	130,385	59,841	(227,612)
Net income (loss) per share attributable to Brooks Automation, Inc. common shareholders:
Basic	$ 0.12	$ 0.15	$ 0.04	$ 0.20	$ 1.03	$ 0.42	$ 0.37	$ 0.19	$ 0.79	$ 0.32	$ 1.83	$ 2.02	$ 0.94	$ (3.62)
Diluted	$ 0.12	$ 0.15	$ 0.04	$ 0.20	$ 1.03	$ 0.41	$ 0.37	$ 0.19	$ 0.78	$ 0.31	$ 1.81	$ 2.01	$ 0.93	$ (3.62)
As Previously Reported
Schedule of Condensed Consolidating Statement of Operations [Line Items]
Equity in earnings of joint ventures		195	1,225	1,164	900	408	310	1,420	718		1,618	2,782	215	(213)
Net income (loss)		9,491	3,006	12,126	66,189	26,603	23,486	12,497	50,089		116,278	128,404	59,025	(227,773)
Net income (loss) attributable to Brooks Automation, Inc.		9,486	2,998	12,098	66,183	26,585	23,486	12,484	50,071		116,254	128,352	58,982	(227,858)
Net income (loss) per share attributable to Brooks Automation, Inc. common shareholders:
Basic		$ 0.15	$ 0.05	$ 0.19	$ 1.02	$ 0.41	$ 0.37	$ 0.19	$ 0.78		$ 1.80	$ 1.99	$ 0.92	$ (3.62)
Diluted		$ 0.14	$ 0.05	$ 0.19	$ 1.02	$ 0.41	$ 0.36	$ 0.19	$ 0.77		$ 1.79	$ 1.97	$ 0.92	$ (3.62)
Adjustment
Schedule of Condensed Consolidating Statement of Operations [Line Items]
Equity in earnings of joint ventures		235	(175)	594	732	238	469	60	707		1,439	2,033	859	246
Net income (loss)		235	(175)	594	732	238	469	60	707		1,439	2,033	859	246
Net income (loss) attributable to Brooks Automation, Inc.		$ 235	$ (175)	$ 594	$ 732	$ 238	$ 469	$ 60	$ 707		$ 1,439	$ 2,033	$ 859	$ 246
Net income (loss) per share attributable to Brooks Automation, Inc. common shareholders:
Basic		$ 0.00	$ 0.00	$ 0.01	$ 0.01	$ 0.00	$ 0.01	$ 0.00	$ 0.01		$ 0.02	$ 0.03	$ 0.01	$ 0.00
Diluted		$ 0.00	$ 0.00	$ 0.01	$ 0.01	$ 0.00	$ 0.01	$ 0.00	$ 0.01		$ 0.02	$ 0.03	$ 0.01	$ 0.00