| Cover Page - shares shares in Thousands | 3 Months Ended | 9 Months Ended | |
| Sep. 30, 2021 | Sep. 30, 2021 | Nov. 30, 2021 | |
| Document Information [Line Items] | |||
| Document Type | 10-Q/A | ||
| Document Quarterly Report | true | ||
| Document Period End Date | Sep. 30, 2021 | ||
| Document Transition Report | false | ||
| Entity File Number | 001-37397 | ||
| Entity Registrant Name | Rimini Street, Inc. | ||
| Entity Incorporation, State or Country Code | DE | ||
| 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 | ||
| Entity Current Reporting Status | Yes | ||
| Entity Interactive Data Current | Yes | ||
| Entity Filer Category | Accelerated Filer | ||
| Entity Small Business | true | ||
| Entity Emerging Growth Company | false | ||
| Entity Shell Company | false | ||
| Entity Common Stock, Shares Outstanding | 86,937 | ||
| Amendment Flag | true | ||
| Document Fiscal Year Focus | 2021 | ||
| Document Fiscal Period Focus | Q3 | ||
| Entity Central Index Key | 0001635282 | ||
| Current Fiscal Year End Date | --12-31 | ||
| Amendment Description | Explanatory NoteRimini Street, Inc. (the “Company”) is filing this Amendment No. 1 (this “Amendment No. 1”) to its quarterly report on Form 10-Q for the quarterly period ended September 30, 2021, as filed with the Securities and Exchange Commission on November 3, 2021 (the “Original Form 10-Q”), in order to correct inadvertent technical errors in paragraph 4 of the certification of its principal executive officer filed as Exhibit 31.1 and the certification of its principal financial officer filed as Exhibit 31.2 to the Original Form 10-Q.This Amendment No. 1 should be read in conjunction with the Original Form 10-Q, which continues to speak as of the date of the Original Form 10-Q. Other than the filing of the corrected certifications mentioned above, this Amendment No. 1 does not modify or update the disclosures in the Original Form 10-Q in any way. Accordingly, this Amendment No. 1 does not reflect events occurring after the filing of the Original Form 10-Q or modify or update any related or other disclosures. | ||
| 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 CommonStock, $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 |
