| Cover | Dec. 09, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Dec. 9, 2020 |
| Entity File Number | 0-7928 |
| Entity Registrant Name | COMTECH TELECOMMUNICATIONS CORP /DE/ |
| Entity Central Index Key | 0000023197 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 11-2139466 |
| Entity Address, Address Line One | 68 South Service Road |
| Entity Address, Address Line Two | Suite 230 |
| Entity Address, City or Town | Melville |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 11747 |
| City Area Code | 631 |
| Local Phone Number | 962-7000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock, par value $0.10 per share | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $0.10 per share |
| Trading Symbol | CMTL |
| Security Exchange Name | NASDAQ |
| Series A Junior Participating Cumulative Preferred Stock, par value $0.10 per share | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Series A Junior Participating Cumulative Preferred Stock, par value $0.10 per share |
