| Document and Entity Information | Aug. 04, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 4, 2021 |
| Entity Registrant Name | INTERNATIONAL MONEY EXPRESS, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-37986 |
| Entity Tax Identification Number | 47-4219082 |
| Entity Address, Address Line One | 9480 South Dixie Highway |
| Entity Address, City or Town | Miami |
| Entity Address, State or Province | FL |
| Entity Address, Postal Zip Code | 33156 |
| City Area Code | 305 |
| Local Phone Number | 671-8000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity Central Index Key | 0001683695 |
| Title of 12(b) Security | Common stock ($0.0001 par value) |
| Trading Symbol | IMXI |
| Security Exchange Name | NASDAQ |
