| Document and Entity Information | May 07, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | May 7, 2021 |
| Entity Registrant Name | Ruths Hospitality Group, Inc. |
| Entity Central Index Key | 0001324272 |
| Entity Emerging Growth Company | false |
| Entity File Number | 000-51485 |
| Entity Incorporation State Country Code | DE |
| Entity Tax Identification Number | 72-1060618 |
| Entity Address, Address Line One | 1030 W. Canton Avenue |
| Entity Address, Address Line Two | Ste. 100 |
| Entity Address, City or Town | Winter Park |
| Entity Address, State or Province | FL |
| Entity Address, Postal Zip Code | 32789 |
| City Area Code | (407) |
| Local Phone Number | 333-7440 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.01 per share |
| Trading Symbol | RUTH |
| Security Exchange Name | NASDAQ |
