Document And Entity Information - shares	3 Months Ended
	Oct. 31, 2015	Nov. 30, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	DONALDSON CO INC
Entity Central Index Key	0000029644
Current Fiscal Year End Date	--07-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Oct. 31, 2015
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		132,650,034