Cover Page - shares	9 Months Ended
	Apr. 30, 2020	May 29, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Apr. 30, 2020
Document Transition Report	false
Entity File Number	001-31337
Entity Registrant Name	Cantel Medical Corp.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	22-1760285
Entity Address, Address Line One	150 Clove Road
Entity Address, City or Town	Little Falls
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07424
City Area Code	(973)
Local Phone Number	890-7220
Title of 12(b) Security	Common Stock
Trading Symbol	CMD
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		42,154,298
Entity Central Index Key	0000019446
Amendment Flag	false
Current Fiscal Year End Date	--07-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3