Joint Ventures - Additional Information (Detail) (USD $)	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012
Schedule of Equity Method Investments [Line Items]
Equity in earnings (losses) of joint ventures	$ (6,000)	$ 1,050,000
Equity investment in joint ventures	30,437,000		31,428,000
ULVAC Cryogenics, Inc.
Schedule of Equity Method Investments [Line Items]
Joint venture interest, percentage	50.00%	50.00%
Equity in earnings (losses) of joint ventures	100,000	900,000
Equity investment in joint ventures	26,800,000
Management fee payments received	100,000	400,000
Charges for products or services	300,000	300,000
Accounts payable for unpaid products and services	200,000		100,000
Yaskawa Brooks Automation, Inc.
Schedule of Equity Method Investments [Line Items]
Joint venture interest, percentage	50.00%	50.00%
Equity in earnings (losses) of joint ventures	(100,000)	200,000
Equity investment in joint ventures	3,700,000
Charges for products or services	100,000	100,000
Accounts payable for unpaid products and services	100,000		100,000
Revenues earned from joint ventures	1,600,000	2,100,000
Amount due from joint ventures	$ 2,000,000		$ 2,000,000