| Cover | Aug. 18, 2020 | Dec. 31, 2020 | Jun. 30, 2021 |
| Document Information [Line Items] | |||
| Entity Central Index Key | 0001635282 | ||
| Amendment Flag | false | ||
| Document Type | 8-K | ||
| Document Period End Date | Jan. 13, 2022 | ||
| Entity Registrant Name | Rimini Street, Inc. | ||
| Entity Incorporation, State or Country Code | DE | ||
| Entity File Number | 001-37397 | ||
| Entity Tax Identification Number | 36-4880301 | ||
| Entity Address, Address Line One | 3993 Howard Hughes Parkway | ||
| Entity Address, Address Line Two | Suite 500 | ||
| Entity Address, City or Town | Las Vegas | ||
| Entity Address, State or Province | NV | ||
| Entity Address, Postal Zip Code | 89169 | ||
| City Area Code | (702) | ||
| Local Phone Number | 839-9671 | ||
| Written Communications | false | ||
| Soliciting Material | false | ||
| Pre-commencement Tender Offer | false | ||
| Pre-commencement Issuer Tender Offer | false | ||
| Entity Emerging Growth Company | false | ||
| Common Stock | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Common Stock, par value $0.0001 per share | ||
| Trading Symbol | RMNI | ||
| Security Exchange Name | NASDAQ | ||
| Public Units | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Public Units, each consisting of one share of Common Stock, $0.0001 par value, and one-half of one Warrant | ||
| Trading Symbol | RMNIU | ||
| Warrant | |||
| Document Information [Line Items] | |||
| Title of 12(b) Security | Warrants, exercisable for one share of Common Stock, $0.0001 par value | ||
| Trading Symbol | RMNIW |
