Document And Entity Information (USD $)	12 Months Ended
	Jul. 31, 2013	Aug. 31, 2013	Jan. 31, 2013
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jul. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Entity Registrant Name	DONALDSON CO INC
Entity Central Index Key	0000029644
Current Fiscal Year End Date	--07-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		146,109,145
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 5,466,451,890
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No