Investment in Affiliates - Additional information (Detail) (USD $)	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Schedule of Equity Method Investments [Line Items]
Equity investment in joint ventures	$ 25,687,000	$ 31,428,000
Equity in earnings of joint ventures	2,442,000	2,133,000	4,815,000
ULVAC Cryogenics, Inc.
Schedule of Equity Method Investments [Line Items]
Joint venture interest, percentage	50.00%			50.00%
Equity investment in joint ventures	22,700,000	27,400,000
Equity in earnings of joint ventures	2,600,000	2,000,000	4,300,000
Management fee payments received	600,000	1,000,000	1,100,000
Charges for products or services	500,000	800,000	400,000
Accounts payable for unpaid products and services	26,000	73,000
Cash dividend received	5,000,000	5,100,000
Yaskawa Brooks Automation, Inc.
Schedule of Equity Method Investments [Line Items]
Joint venture interest, percentage	50.00%			50.00%
Equity investment in joint ventures	3,000,000	4,000,000
Equity in earnings of joint ventures	(200,000)	100,000	500,000
Revenues earned from joint ventures	6,300,000	8,000,000	9,600,000
Due from joint venture	2,300,000	2,000,000
Charges for products or services	500,000	500,000	300,000
Accounts payable for unpaid products and services	$ 47,000	$ 58,000