| Document and Entity Information | Sep. 22, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 22, 2021 |
| Entity Registrant Name | TIVITY HEALTH, INC. |
| Entity Central Index Key | 0000704415 |
| Entity Emerging Growth Company | false |
| Entity File Number | 000-19364 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 62-1117144 |
| Entity Address, Address Line One | 701 Cool Springs Boulevard |
| Entity Address, City or Town | Franklin |
| Entity Address, State or Province | TN |
| Entity Address, Postal Zip Code | 37067 |
| City Area Code | 800 |
| Local Phone Number | 869-5311 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of each class | Common Stock - $.001 par value |
| Trading Symbol | TVTY |
| Name of each exchange on which registered | NASDAQ |
