| COVER PAGE | Oct. 21, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Oct. 21, 2021 |
| Entity Registrant Name | Green Dot Corp |
| Entity Central Index Key | 0001386278 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-34819 |
| Entity Tax Identification Number | 95-4766827 |
| Entity Address, Address Line One | 3465 E. Foothill Blvd. |
| Entity Address, City or Town | Pasadena, |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 91107 |
| City Area Code | (626) |
| Local Phone Number | 765-2000 |
| 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, $0.001 par value |
| Trading Symbol | GDOT |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
