v3.26.1
SEGMENT INFORMATION - Reconciliation of Segment Information to Consolidated Information (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting Information [Line Items]        
Revenues $ 4,384.6 $ 4,373.1 $ 8,497.6 $ 8,521.6
Cost of sales (3,631.5) (3,621.2) (7,017.7) (7,045.5)
Depreciation and amortization 23.1 19.0 45.6 38.2
Floor plan interest expense 21.6 18.1 42.7 38.8
INCOME FROM OPERATIONS (219.5) (257.4) (413.4) (491.7)
Asset impairments (4.2) 0.0 (4.2) (14.3)
Other interest expense, net (46.5) (41.4) (94.6) (83.7)
Gain on divestitures, net 0.0 5.9 125.8 10.1
Income before income taxes 151.3 203.8 401.9 379.2
Finance and insurance, net        
Segment Reporting Information [Line Items]        
Revenues 183.8 182.0 362.9 368.9
Cost of sales (12.4) (13.8) (24.6) (26.9)
Parts and service        
Segment Reporting Information [Line Items]        
Revenues 634.6 601.5 1,261.4 1,189.1
Cost of sales (260.4) (246.7) (522.1) (491.6)
New vehicle        
Segment Reporting Information [Line Items]        
Revenues 2,330.2 2,303.9 4,431.0 4,442.0
Cost of sales (2,192.0) (2,143.9) (4,164.3) (4,138.9)
Used vehicle        
Segment Reporting Information [Line Items]        
Revenues 1,236.0 1,285.8 2,442.3 2,521.6
Cost of sales (1,166.6) (1,216.8) (2,306.7) (2,388.1)
Dealerships        
Segment Reporting Information [Line Items]        
Revenues 4,302.4 4,293.6 8,334.2 8,358.0
TCA        
Segment Reporting Information [Line Items]        
Revenues 82.2 79.5 163.4 163.6
Operating Segments        
Segment Reporting Information [Line Items]        
Revenues 4,456.4 4,447.3 8,633.6 8,658.1
INCOME FROM OPERATIONS (218.1) (250.6) (397.5) (480.1)
Operating Segments | Dealerships        
Segment Reporting Information [Line Items]        
Revenues 4,374.2 4,367.8 8,470.1 8,494.5
Personnel costs 315.7 318.8 633.9 627.8
Rent and related expenses 41.0 28.6 83.5 49.8
Advertising 16.2 17.1 34.2 32.3
Other selling, general and administrative expense 132.2 116.5 265.5 229.0
Other segment items 0.0 0.0 0.0 0.0
Depreciation and amortization 23.0 19.0 45.6 38.1
Floor plan interest expense 21.6 18.1 42.7 38.8
INCOME FROM OPERATIONS (196.9) (232.1) (355.1) (440.5)
Operating Segments | Dealerships | Finance and insurance, net        
Segment Reporting Information [Line Items]        
Cost of sales 0.0 0.0 0.0 0.0
Operating Segments | Dealerships | Parts and service        
Segment Reporting Information [Line Items]        
Cost of sales (268.8) (256.9) (538.6) (511.2)
Operating Segments | Dealerships | New vehicle        
Segment Reporting Information [Line Items]        
Cost of sales (2,192.0) (2,143.9) (4,164.3) (4,138.9)
Operating Segments | Dealerships | Used vehicle        
Segment Reporting Information [Line Items]        
Cost of sales (1,166.6) (1,216.8) (2,306.7) (2,388.1)
Operating Segments | TCA        
Segment Reporting Information [Line Items]        
Revenues 82.2 79.5 163.4 163.6
Personnel costs 0.0 0.0 0.0 0.0
Rent and related expenses 0.0 0.0 0.0 0.0
Advertising 0.0 0.0 0.0 0.0
Other selling, general and administrative expense 0.0 0.0 0.0 0.0
Other segment items 1.8 1.7 3.7 3.6
Depreciation and amortization 0.0 0.1 0.0 0.1
Floor plan interest expense 0.0 0.0 0.0 0.0
INCOME FROM OPERATIONS (21.1) (18.5) (42.4) (39.6)
Operating Segments | TCA | Finance and insurance, net        
Segment Reporting Information [Line Items]        
Cost of sales (59.2) (59.3) (117.3) (120.3)
Operating Segments | TCA | Parts and service        
Segment Reporting Information [Line Items]        
Cost of sales 0.0 0.0 0.0 0.0
Operating Segments | TCA | New vehicle        
Segment Reporting Information [Line Items]        
Cost of sales 0.0 0.0 0.0 0.0
Operating Segments | TCA | Used vehicle        
Segment Reporting Information [Line Items]        
Cost of sales 0.0 0.0 0.0 0.0
Intersegment Eliminations        
Segment Reporting Information [Line Items]        
Revenues (71.8) (74.1) (136.0) (136.5)
Cost of sales 55.2 55.6 109.3 112.9
INCOME FROM OPERATIONS (16.0) (11.3) (22.6) (12.9)
Deferral of SG&A expense (related to capitalized contract costs offset by amortization) 0.6 7.2 4.1 10.7
Intersegment Eliminations | Finance and insurance, net        
Segment Reporting Information [Line Items]        
Revenues (63.4) (63.9) (119.4) (117.0)
Intersegment Eliminations | Parts and service        
Segment Reporting Information [Line Items]        
Revenues (8.4) (10.2) (16.5) (19.5)
Intersegment Eliminations | Dealerships        
Segment Reporting Information [Line Items]        
Revenues (71.8) (74.1) (136.0) (136.5)
Intersegment Eliminations | Dealerships | Finance and insurance, net        
Segment Reporting Information [Line Items]        
Revenues (63.4) (63.9) (119.4) (117.0)
Intersegment Eliminations | Dealerships | Parts and service        
Segment Reporting Information [Line Items]        
Revenues (8.4) (10.2) (16.5) (19.5)
Intersegment Eliminations | TCA        
Segment Reporting Information [Line Items]        
Revenues 0.0 0.0 0.0 0.0
Intersegment Eliminations | TCA | Finance and insurance, net        
Segment Reporting Information [Line Items]        
Revenues 0.0 0.0 0.0 0.0
Intersegment Eliminations | TCA | Parts and service        
Segment Reporting Information [Line Items]        
Revenues $ 0.0 $ 0.0 $ 0.0 $ 0.0