| In millions, except per share items | Jan-01-23 | Jan-02-22 | Jan-03-21 | Dec-29-19 | Dec-30-18 | Dec-31-17 | Jan-01-17 | Jan-03-16 |
| | 8-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Revenues: | | | | | | | | |
| Revenues | 387.4 | 357.3 | 315.4 | 363.5 | 688.6 | 669.1 | 1,245.6 | 687.4 |
| Revenues growth | 8.4% | 13.3% | -13.2% | -47.2% | 2.9% | -46.3% | 81.2% | 12.5% |
| Costs and expenses: | | | | | | | | |
| Cost of sales | | 108.6 | 100.1 | 115.1 | 218.9 | 202.9 | 214.6 | |
| Restaurant wages and related expenses | | 91.7 | 74.3 | 84.9 | 188.1 | 184.7 | 185.3 | 174.2 |
| Other restaurant operating expenses | | 57.4 | 47.8 | 50.3 | 100.8 | 98.9 | 96.5 | 87.3 |
| General and administrative | | 45.5 | 39.8 | 41.9 | 54.5 | 59.6 | 54.8 | 54.5 |
| Depreciation and amortization | 20.1 | 20.6 | 22.0 | 22.2 | 37.6 | 35.0 | 36.8 | 30.6 |
| |
| Pre-opening costs | | | | | | | | |
| Impairment and other lease charges (recoveries) | 1.4 | 1.5 | 8.0 | 0.0 | 21.1 | 61.8 | 25.6 | 2.4 |
| |
| Goodwill impairment | | | | | | | | |
| Closed restaurant rent expense, net of sublease income | | 3.0 | 4.3 | 3.3 | | | | |
| Other expense (income), net | | 0.5 | -2.1 | 0.9 | -3.0 | 2.2 | 1.1 | -0.7 |
| Income (loss) from operations | -14.4 | -6.6 | -10.1 | 10.2 | 9.0 | -41.1 | 27.2 | 62.5 |
| Operating margin | -3.7% | -1.9% | -3.2% | 2.8% | 1.3% | -6.1% | 2.2% | 9.1% |
| Interest expense (income), net | -0.3 | -0.4 | -0.3 | -0.3 | -4.0 | -2.9 | -2.2 | -1.9 |
| Provision for income taxes | 1.0 | 1.1 | -7.0 | 11.8 | -2.8 | -7.8 | 8.3 | 22.0 |
| Net income (loss) | -14.6 | 10.4 | -10.2 | -84.4 | 7.8 | -36.2 | 16.7 | 38.5 |
| |
| Earnings (loss) per common share: | | | | | | | | |
| |
| Basic (usd per share) | ($0.58) | $0.40 | ($0.40) | ($3.18) | $0.29 | ($1.35) | $0.62 | $1.44 |
| Diluted (usd per share) | ($0.58) | $0.40 | ($0.40) | ($3.18) | $0.29 | ($1.35) | $0.62 | $1.44 |
| |
| Weighted average common shares outstanding: | | | | | | | | |
| Basic (in shares) | 25.0 | 25.4 | 25.3 | 26.5 | 26.9 | 26.8 | 26.7 | 26.5 |
| Diluted (in shares) | 25.0 | 25.4 | 25.3 | 26.5 | 26.9 | 26.8 | 26.7 | 26.5 |