Joint Ventures Narrative (Detail) (USD $)	3 Months Ended			9 Months Ended
	Jun. 30, 2013	Sep. 30, 2012	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Schedule of Equity Method Investments [Line Items]
Equity in earnings (losses) of joint ventures	$ 236,000		$ 196,000	$ 220,000	$ 1,676,000
Equity investment in joint ventures	23,582,000	31,428,000		23,582,000
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			300,000	363,000	1,800,000
Equity investment in joint ventures	20,500,000			20,500,000
Management fee payments received	200,000			400,000	800,000
Charges incurred from related parties	100,000		200,000	500,000	700,000
Accounts payable for unpaid products and services	26,000	100,000		26,000
Cash dividend received from equity investment	4,600,000	5,100,000
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)		(100,000)
Equity investment in joint ventures	3,100,000			3,100,000
Charges incurred from related parties			100,000	400,000	300,000
Accounts payable for unpaid products and services	100,000	100,000		100,000
Revenues earned from joint ventures	1,200,000		1,700,000	4,100,000	5,700,000
Due from joint venture	$ 1,900,000		$ 2,000,000	$ 1,900,000	$ 2,000,000