Document and Entity Information	3 Months Ended
	Dec. 31, 2013	Jan. 28, 2014
Document and Entity Information [Abstract]
Trading Symbol	BRKS
Entity Registrant Name	BROOKS AUTOMATION INC
Entity Central Index Key	0000933974
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Dec. 31, 2013
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		66,645,113