Cover Page Cover Page - USD ($)	12 Months Ended
	Jul. 31, 2020	Jan. 31, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Jul. 31, 2020
Document Transition Report	false
Entity File Number	001-12622
Entity Registrant Name	OIL-DRI CORPORATION OF AMERICA
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-2048898
Entity Address, Address Line One	410 North Michigan Avenue
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60611-4213
City Area Code	312
Local Phone Number	321-1515
Title of 12(b) Security	Common Stock, par value $0.10 per share
Trading Symbol	ODC
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
ICFR Auditor Attestation Flag	true
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Shell Company	false
Entity Public Float		$ 193,493,002
Entity Central Index Key	0000074046
Current Fiscal Year End Date	--07-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Emerging Growth Company	false
Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	5,383,876
Common Class B
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	2,078,283
Common Class A
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	0