| Cover | Nov. 19, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Document Period End Date | Nov. 19, 2020 |
| Entity Registrant Name | i3 Verticals, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-38532 |
| Entity Tax Identification Number | 82-4052852 |
| Entity Address, Address Line One | 40 Burton Hills Blvd., Suite 415 |
| Entity Address, City or Town | Nashville |
| Entity Address, State or Province | TN |
| Entity Address, Postal Zip Code | 37215 |
| City Area Code | 615 |
| Local Phone Number | 465-4487 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Class A Common Stock, $0.0001 Par Value |
| Trading Symbol | IIIV |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001728688 |
| Amendment Flag | true |
