| Basis of Presentation (Policies) | 3 Months Ended |
| Apr. 02, 2023 |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
| Basis of Consolidation | Basis of Consolidation. The unaudited condensed consolidated financial statements presented herein reflect the consolidated financial position, results of operations and cash flows of Fiesta and its wholly-owned subsidiaries. All intercompany transactions have been eliminated in consolidation. |
| Fiscal Year | Fiscal Year . The Company uses a 52–53 week fiscal year ending on the Sunday closest to December 31. The fiscal year ended January 1, 2023 contained 52 weeks. The three months ended April 2, 2023 and April 3, 2022 each contained thirteen weeks, respectively. The fiscal year ending December 31, 2023 will contain 52 weeks. |
| Basis of Presentation | Basis of Presentation. The accompanying unaudited condensed consolidated financial statements for the three months ended April 2, 2023 and April 3, 2022 have been prepared without an audit pursuant to the rules and regulations of the Securities and Exchange Commission and do not include certain information and footnotes required by U.S. Generally Accepted Accounting Principles ("GAAP") for complete financial statements. In the opinion of management, all normal and recurring adjustments considered necessary for a fair presentation of such financial statements have been included. The results of operations for the three months ended April 2, 2023 and April 3, 2022 are not necessarily indicative of the results to be expected for the full year. |
| Reclassification | Reclassification. Certain prior period balances have been reclassified to conform to the current period presentation in the accompanying notes to the condensed consolidated financial statements. |
| Revenue Recognition | Revenue Recognition. Revenue is recognized upon transfer of promised products or services to customers in an amount that reflects the consideration the Company received in exchange for those products or services. Revenues from the Company's owned and operated restaurants are recognized when payment is tendered at the time of sale. Franchise royalty revenues are based on a percentage of gross sales and are recorded as income when earned. Initial franchise fees and area development fees associated with new franchise agreements are not distinct from the continuing rights and services offered by the Company during the term of the related franchise agreements and are recognized as income over the term of the related franchise agreements. A portion of the initial franchise fee is allocated to training services and is recognized as revenue when the Company completes the training services. |
| Fair Value of Financial Instruments | Fair Value of Financial Instruments. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date under current market conditions. In determining fair value, the accounting standards establish a three-level hierarchy for inputs used in measuring fair value as follows: Level 1 inputs are quoted prices in active markets for identical assets or liabilities; Level 2 inputs are observable for the asset or liability, either directly or indirectly, including quoted prices in active markets for similar assets or liabilities; and Level 3 inputs are unobservable and reflect management's own assumptions. The following methods were used to estimate the fair value of each class of financial instruments for which it is practicable to estimate the fair value: • Current Assets and Liabilities. The carrying values reported on the condensed consolidated balance sheets of cash and restricted cash, accounts receivable and accounts payable approximate fair value because of the short maturity of those financial instruments. • Revolving Credit Borrowings. |
| Long-Lived Assets | Long-Lived Assets. The Company assesses the recoverability of property and equipment and definite-lived intangible assets, including right-of-use ("ROU") lease assets, by determining whether the carrying value of these assets can be recovered over their respective remaining lives through undiscounted future operating cash flows. Impairment is reviewed whenever events or changes in circumstances indicate that the carrying amounts of these assets may not be fully recoverable. |
| Leases | Leases. The Company assesses whether an agreement contains a lease at inception. All leases are reviewed for finance or operating classification once control is obtained. The majority of the Company's leases are operating leases. Operating leases are included within operating lease right-of-use assets, other current liabilities, and operating lease liabilities in the condensed consolidated balance sheets. Finance leases are included within property and equipment, net, current portion of long-term debt, and long-term debt, net of current portion in the condensed consolidated balance sheets. |
| Use of Estimates | Use of Estimates. The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of the financial statements. Estimates also affect the reported amounts of expenses during the reporting periods. Significant items subject to such estimates and assumptions include: insurance liabilities, evaluation for impairment of goodwill and long-lived assets, lease accounting matters, and deferred income tax assets. Actual results could differ from those estimates. |
| Impairment of Long-Lived Assets | The Company reviews its long-lived assets, principally property and equipment and lease ROU assets, for impairment at the restaurant level. The Company has elected to exclude operating lease payments and liabilities from future cash flows and carrying values, respectively, in its impairment review. In addition to considering management's plans, known regulatory or governmental actions and damage due to acts of God (hurricanes, tornadoes, etc.), the Company considers a triggering event to have occurred related to a specific restaurant if the restaurant's cash flows, exclusive of operating lease payments, for the last twelve months are less than a minimum threshold or if consistent levels of cash flows for the remaining lease period are less than the carrying value of the restaurant's assets. If an indicator of impairment exists for any of its assets, an estimate of undiscounted future cash flows, exclusive of operating lease payments, over the life of the primary asset for each restaurant is compared to that long-lived asset group's carrying value, excluding operating lease liabilities. If the carrying value is greater than the undiscounted cash flow, the Company then determines the fair value of the asset and if an asset is determined to be impaired, the loss is measured by the excess of the carrying amount of the asset over its fair value. There is uncertainty in the projected undiscounted future cash flows used in the Company's impairment review analysis. If actual performance does not achieve the projections, the Company may recognize impairment charges in future periods, and such charges could be material. |
| Purchase of Treasury Stock | Purchase of Treasury StockIn 2018, the Company's board of directors approved a share repurchase program for up to 1,500,000 shares of the Company's common stock. In 2019, the Company's board of directors approved increases to the share repurchase program of an additional 1,500,000 shares of the Company's common stock for an aggregate approval of 3,000,000 shares of the Company's common stock. Under the share repurchase program, shares may be repurchased from time to time in open market transactions at prevailing market prices, in privately negotiated transactions or by other means in accordance with federal securities laws, including Rule 10b-18 under the Securities Exchange Act of 1934, as amended. The share repurchase program has no time limit and may be modified, suspended, superseded or terminated at any time by the Company's board of directors. The Company repurchased 14,746 shares of common stock valued at approximately $0.2 million during the three months ended April 3, 2022. As of April 2, 2023, 137,462 shares of common stock remain available for purchase under the share repurchase program. Additionally, as a result of net share settlement to satisfy the minimum statutory tax withholding requirements in connection with the vesting of restricted stock grants for certain employees, the Company repurchased 63,774 shares of common stock valued at approximately $0.5 million during the three months ended April 2, 2023. The repurchased shares are held as treasury stock at cost. |
| Earnings per Share | Basic earnings (loss) per share ("EPS") is computed by dividing net income (loss) applicable to common shares by the weighted average number of common shares outstanding during each period. Non-vested restricted shares contain a non-forfeitable right to receive dividends on a one-to-one per share ratio to common shares and are thus considered participating securities. The impact of the participating securities is included in the computation of basic EPS pursuant to the two-class method. The two-class method of computing EPS is an earnings allocation formula that determines earnings attributable to common shares and participating securities according to dividends declared (whether paid or unpaid) and participation rights in undistributed earnings. EPS is computed by dividing undistributed earnings allocated to common stockholders by the weighted average number of common shares outstanding for the period. In applying the two-class method, undistributed earnings are allocated to both common shares and non-vested restricted shares based on the weighted average shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if the restricted stock units were to be converted into common shares. Restricted stock units with performance conditions are only included in the diluted EPS calculation to the extent that performance conditions have been met at the measurement date. Diluted EPS is computed by adjusting the basic weighted |
