Document and Entity Information (USD $)	12 Months Ended
	Apr. 30, 2011	Jun. 14, 2011	Oct. 31, 2010
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Apr. 30, 2011
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2011
Entity Registrant Name	FLOW INTERNATIONAL CORP
Entity Central Index Key	0000713002
Current Fiscal Year End Date	--04-30
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		47,430,992
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 119,923,022
Entity Current Reporting Status	Yes
Entity Voluntary Filers	Yes