| Fiscal period | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
| Period End Date | 12/31/2025 | 12/31/2024 | 12/31/2023 | 12/31/2022 | 12/31/2021 | 12/31/2020 | 12/31/2019 | 12/31/2018 | 12/31/2017 | 12/31/2016 |
| New vehicle | 10,989.90 | 9,972.40 | 8,774.60 | 7,452.50 | 6,504.80 | 5,580.80 | 6,314.10 | 6,181.37 | 6,157.53 | 6,046.08 |
| Used vehicle retail sales | 7,195.00 | 6,179.90 | 5,693.50 | 5,673.30 | 4,438.80 | 3,105.70 | 3,366.60 | 3,166.07 | 2,798.99 | 2,757.71 |
| Used vehicle wholesale sales | 607.30 | 462.40 | 441.40 | 364.60 | 365.70 | 308.10 | 355.20 | 369.58 | 400.17 | 401.86 |
| Parts and service sales | 2,844.60 | 2,491.00 | 2,222.30 | 2,009.50 | 1,591.20 | 1,389.30 | 1,510.00 | 1,416.89 | 1,338.03 | 1,261.31 |
| Other dealership revenues, net | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Finance, insurance and other, net | 934.60 | 828.70 | 741.90 | 722.20 | 581.40 | 467.90 | 497.90 | 467.45 | 429.00 | 420.65 |
| Retail finance fees | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Vehicle service contract fees | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Total Revenues | 22,571.40 | 19,934.30 | 17,873.70 | 16,222.10 | 13,481.90 | 10,851.80 | 12,043.80 | 11,601.36 | 11,123.72 | 10,887.61 |
| New vehicle | 10,234.50 | 9,254.50 | 8,007.60 | 6,627.00 | 5,894.00 | 5,250.40 | 6,013.30 | 5,870.50 | 5,835.53 | 5,729.70 |
| Used vehicle retail sales | 6,847.80 | 5,849.90 | 5,392.60 | 5,359.60 | 4,084.60 | 2,896.90 | 3,165.30 | 2,980.14 | 2,621.43 | 2,575.23 |
| Used vehicle wholesale sales | 608.20 | 465.70 | 445.20 | 364.60 | 340.90 | 297.10 | 354.10 | 367.88 | 402.91 | 406.31 |
| Parts and service sales | 1,259.00 | 1,123.20 | 1,008.00 | 905.80 | 721.80 | 638.50 | 695.00 | 657.74 | 618.34 | 581.31 |
| Gross Profit | 3,621.80 | 3,241.00 | 3,020.30 | 2,965.20 | 2,440.70 | 1,769.00 | 1,816.00 | 1,725.09 | 1,645.51 | 1,595.07 |
| Depreciation expense | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Depreciation and amortization expense | 121.10 | 113.10 | 92.00 | 88.40 | 77.40 | 75.80 | 71.60 | 67.07 | 57.94 | 51.23 |
| Amortization expense | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Selling, general and administrative expenses | 2,545.50 | 2,179.20 | 1,926.80 | 1,783.30 | 1,477.20 | 1,169.30 | 1,358.40 | 1,273.06 | 1,226.20 | 1,170.76 |
| Restructuring charges | 28.40 | 16.70 | -- | -- | -- | -- | -- | -- | -- | -- |
| Other operating (income) expense | -- | 10.00 | -- | -- | -- | -- | -- | -- | -- | -- |
| Asset impairments | (192.80) | (33.00) | (32.90) | (2.10) | (1.70) | (37.70) | (22.20) | (43.88) | (19.51) | (32.84) |
| Operating Income (Loss) | 734.00 | 909.10 | 968.60 | 1,091.40 | 884.40 | 486.10 | 363.70 | 341.08 | 341.87 | 340.23 |
| Floorplan interest expense | 101.50 | 108.50 | 64.10 | 27.30 | 27.60 | 39.50 | 61.60 | 59.88 | 52.37 | 44.93 |
| Other interest expense, net | 182.90 | 141.30 | 99.80 | 77.50 | 55.80 | 62.60 | 74.90 | 75.80 | 70.50 | 67.94 |
| Other income (expense), net | 0.20 | (0.70) | (4.50) | (1.20) | -- | -- | -- | -- | -- | -- |
| Loss on extinguishment of long-term debt | -- | -- | -- | -- | -- | (13.70) | -- | -- | -- | -- |
| Gain on redemption of senior subordinated notes | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Income (loss) before income taxes | 449.90 | 658.50 | 800.20 | 985.30 | 800.90 | 370.30 | 227.30 | 205.40 | 219.00 | 227.37 |
| Provision for income taxes | 126.20 | 161.50 | 198.20 | 231.10 | 175.50 | 83.80 | 53.30 | 47.63 | 5.56 | 80.31 |
| Federal-Current | 75.60 | 121.40 | 142.90 | 160.70 | 116.40 | 70.80 | -- | 35.92 | 44.92 | 57.32 |
| Federal-Deferred | 35.00 | 14.70 | 11.80 | 24.60 | 30.70 | 5.40 | -- | 2.60 | (46.94) | 18.70 |
| State-Current | 12.20 | 19.20 | 23.80 | 24.50 | 13.80 | 7.00 | -- | 4.33 | 3.77 | 4.64 |
| State-Deferred | 8.20 | 4.60 | 4.60 | 5.90 | 1.60 | (1.30) | -- | 0.88 | 3.92 | 1.88 |
| Foreign-current | 13.60 | (2.70) | 12.80 | 18.00 | 14.80 | 7.00 | -- | 3.91 | 2.93 | 4.19 |
| Foreign-deferred | (18.40) | 4.30 | 2.30 | (2.60) | (1.80) | (5.10) | -- | (0.01) | (3.05) | (6.42) |
| Income (loss) from Continuing Operations | 323.70 | 497.00 | 602.00 | 754.20 | 625.40 | -- | -- | -- | -- | -- |
| Loss related to discontinued operations | 1.50 | 1.20 | (0.40) | (2.70) | (73.30) | -- | -- | -- | -- | -- |
| Income tax benefit related to losses on discontinued operations | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Income Before Extraordinary Income & Accounting Change | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Cumulative effect of a change in accounting principle, net of tax | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Consolidated Net Income (Loss) | 325.20 | 498.10 | 601.60 | 751.50 | 552.10 | 286.50 | 174.00 | 157.77 | 213.44 | 147.07 |
| Earnings allocated to participating securities for basic | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Earnings allocated to participating securities for diluted | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Less: Earnings allocated to participating securities | 3.70 | 10.50 | -- | 21.20 | 18.60 | 10.30 | 6.40 | 5.42 | 7.51 | 5.87 |
| Net Income (Loss) Available to Common Shareholders | 321.50 | 487.60 | 601.60 | 730.30 | 533.50 | 276.20 | 167.60 | 152.36 | 205.93 | 141.20 |
| Earnings available to basic common shares | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Earnings available to diluted common shares | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Basic:Income from Continuing Operations | 25.17 | 36.88 | 42.92 | 47.46 | 34.23 | -- | -- | -- | -- | -- |
| Basic: Loss per share from discontinuing operations | 0.12 | 0.09 | (0.03) | (0.17) | (4.01) | -- | -- | -- | -- | -- |
| Basic:Cumulative effect of a change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Basic:Net income | 25.29 | 36.96 | 42.89 | 47.29 | 30.22 | 15.55 | 9.35 | 7.83 | 10.08 | 6.67 |
| Diluted:Income from Continuing Operations | 25.13 | 36.72 | 42.75 | 47.31 | 34.11 | -- | -- | -- | -- | -- |
| Diluted: Loss per share from discontinuing operations | 0.12 | 0.09 | (0.03) | (0.17) | (4.00) | -- | -- | -- | -- | -- |
| Diluted:Cumulative effect of a change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Diluted:Net income | 25.24 | 36.81 | 42.73 | 47.14 | 30.11 | 15.51 | 9.34 | 7.83 | 10.08 | 6.67 |
| Weighted Average Shares Outstanding (Basic) | 12.70 | 13.20 | 13.70 | 15.40 | 17.70 | 17.80 | 17.90 | 19.45 | 20.42 | 21.16 |
| Weighted Average Shares Outstanding (Diluted) | 12.70 | 13.20 | 13.70 | 15.50 | 17.70 | 17.80 | 17.90 | 19.46 | 20.43 | 21.17 |