| Document and Entity Information | Nov. 05, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | J. Alexander's Holdings, Inc. |
| Document Period End Date | Nov. 5, 2020 |
| Amendment Flag | false |
| Entity Central Index Key | 0001617227 |
| Document Type | 8-K |
| Entity Incorporation State Country Code | TN |
| Entity File Number | 001-37473 |
| Entity Tax Identification Number | 47-1608715 |
| Entity Address, Address Line One | 3401 West End Avenue |
| Entity Address, Address Line Two | Suite 260 |
| Entity Address, Address Line Three | P.O. Box 24300 |
| Entity Address, City or Town | Nashville |
| Entity Address, State or Province | TN |
| Entity Address, Postal Zip Code | 37202 |
| City Area Code | (615) |
| Local Phone Number | 269-1900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.001 per share |
| Trading Symbol | JAX |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | true |
