| Cover | Dec. 18, 2020 | Mar. 05, 2020 |
| Cover [Abstract] | ||
| Document Type | 8-K | |
| Document Period End Date | Dec. 16, 2020 | |
| Entity Registrant Name | CANTEL MEDICAL CORP. | |
| Entity Incorporation, State or Country Code | DE | |
| Entity File Number | 001-31337 | |
| 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 | |
| Written Communications | false | |
| Soliciting Material | false | |
| Pre-commencement Tender Offer | false | |
| Pre-commencement Issuer Tender Offer | false | |
| Entity Emerging Growth Company | false | |
| Entity Central Index Key | 0000019446 | |
| Amendment Flag | false | |
| Amendment Description |
