| Document and Entity Information | Oct. 28, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Oct. 28, 2021 |
| Entity Registrant Name | ENOVA INTERNATIONAL, INC. |
| Entity Central Index Key | 0001529864 |
| Entity Emerging Growth Company | false |
| Entity File Number | 1-35503 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 45-3190813 |
| Entity Address, Address Line One | 175 West Jackson Boulevard |
| Entity Address, City or Town | Chicago |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60604 |
| City Area Code | (312) |
| Local Phone Number | 568-4200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of Each Class | Common stock, par value $0.00001 per share |
| Trading symbol(s) | ENVA |
| Name of Exchange of which registered | NYSE |
