| Document and Entity Information | Nov. 02, 2021 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 2, 2021 |
| Entity File Number | 001-35108 |
| Entity Registrant Name | ServiceSource International, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 81-0578975 |
| Entity Address, Address Line One | 707 17th Street |
| Entity Address, Adress Line Two | 25th Floor |
| Entity Address, City or Town | Denver |
| Entity Address, State or Province | CO |
| Entity Address, Postal Zip Code | 80202 |
| City Area Code | 720 |
| Local Phone Number | 889-8500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.0001 Par Value |
| Trading Symbol | SREV |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001310114 |
| Amendment Flag | false |
