Segment Information Financial Information for Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014
Revenue
Product	$ 116,395us-gaap_SalesRevenueGoodsNet	$ 102,534us-gaap_SalesRevenueGoodsNet	$ 216,125us-gaap_SalesRevenueGoodsNet	$ 195,664us-gaap_SalesRevenueGoodsNet
Services	22,918us-gaap_SalesRevenueServicesNet	23,366us-gaap_SalesRevenueServicesNet	45,924us-gaap_SalesRevenueServicesNet	47,308us-gaap_SalesRevenueServicesNet
Total revenues	139,313us-gaap_SalesRevenueNet	125,900us-gaap_SalesRevenueNet	262,049us-gaap_SalesRevenueNet	242,972us-gaap_SalesRevenueNet
Gross profit	46,025us-gaap_GrossProfit	44,298us-gaap_GrossProfit	85,113us-gaap_GrossProfit	85,189us-gaap_GrossProfit
Segment operating income (loss)	3,053us-gaap_OperatingIncomeLoss	2,396us-gaap_OperatingIncomeLoss	(3,427)us-gaap_OperatingIncomeLoss	3,854us-gaap_OperatingIncomeLoss
Total assets	756,955us-gaap_Assets		756,955us-gaap_Assets		778,038us-gaap_Assets
Brooks Product Solutions
Revenue
Product	98,958	89,897	181,814	171,453
Services	0	0	0	0
Total revenues	98,958	89,897	181,814	171,453
Gross profit	33,995	31,960	60,917	60,461
Segment operating income (loss)	7,995	6,127	8,457	10,455
Total assets	259,393		259,393		252,944
Brooks Global Services
Revenue
Product	4,128	4,213	8,236	7,652
Services	18,709	19,178	37,798	39,058
Total revenues	22,837	23,391	46,034	46,710
Gross profit	7,043	7,676	15,506	15,501
Segment operating income (loss)	2,108	2,248	5,661	5,091
Total assets	55,809		55,809		58,678
Brooks Life Science Systems
Revenue
Product	13,309	8,424	26,075	16,559
Services	4,209	4,188	8,126	8,250
Total revenues	17,518	12,612	34,201	24,809
Gross profit	4,987	4,662	8,690	9,227
Segment operating income (loss)	(4,391)	(3,565)	(9,907)	(7,040)
Total assets	117,249		117,249		103,498
Operating Segments
Revenue
Product	116,395	102,534	216,125	195,664
Services	22,918	23,366	45,924	47,308
Total revenues	139,313	125,900	262,049	242,972
Gross profit	46,025	44,298	85,113	85,189
Segment operating income (loss)	5,712	4,810	4,211	8,506
Total assets	$ 432,451		$ 432,451		$ 415,120

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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