Segment Information Financial Information for Business Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2012
Revenues
Product	$ 95,493	$ 117,621	$ 172,816	$ 214,719
Services	21,126	21,716	41,828	44,846
Total revenues	116,619	139,337	214,644	259,565
Gross profit	36,612	48,282	65,770	88,639
Segment operating income (loss)	(972)	8,415	(14,036)	9,878
Total assets	721,762		721,762		741,960
Brooks Product Solutions
Revenues
Product	85,404	103,456	148,126	188,750
Services	0	0	0	0
Total revenues	85,404	103,456	148,126	188,750
Gross profit	27,685	35,885	45,439	64,286
Segment operating income (loss)	3,523	7,597	(2,911)	8,682
Total assets	251,174		251,174		218,799
Brooks Global Services
Revenues
Product	3,731	3,015	7,236	5,392
Services	18,369	18,220	36,029	37,937
Total revenues	22,100	21,235	43,265	43,329
Gross profit	6,516	6,591	11,626	13,727
Segment operating income (loss)	1,956	2,195	2,547	5,144
Total assets	63,799		63,799		56,120
Brooks Life Science Systems
Revenues
Product	6,358	11,150	17,454	20,577
Services	2,757	3,496	5,799	6,909
Total revenues	9,115	14,646	23,253	27,486
Gross profit	2,411	5,806	8,705	10,626
Segment operating income (loss)	(3,875)	(105)	(3,897)	(738)
Total assets	100,102		100,102		107,530
Operating Segments
Revenues
Product	95,493	117,621	172,816	214,719
Services	21,126	21,716	41,828	44,846
Total revenues	116,619	139,337	214,644	259,565
Gross profit	36,612	48,282	65,770	88,639
Segment operating income (loss)	1,604	9,687	(4,261)	13,088
Total assets	$ 415,075		$ 415,075		$ 382,449