v3.26.1
Segment Information (Details)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
segments
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
Segment Reporting Information [Line Items]          
Number of reportable segments | segments     4    
Revenues from external customers $ 6,929.8 $ 6,974.4 $ 13,481.9 $ 13,664.8  
Cost of sales:          
Total cost of sales 5,698.7 5,699.0 11,039.7 11,169.5  
Selling, general and administrative expenses:          
Total selling, general, and administrative expenses 856.3 854.7 1,698.5 1,676.6  
Depreciation and amortization 63.5 63.9 126.5 125.7  
Floorplan interest expense 43.7 45.3 85.5 91.8  
AutoNation Finance:          
AutoNation Finance income 10.7 2.0 20.1 2.1  
Corporate and other (89.8) (235.2) (173.4) (319.7)  
Other interest expense (49.9) (46.2) (97.9) (88.5)  
Other income (loss), net 18.4 12.3 69.6 (0.9)  
INCOME BEFORE INCOME TAXES 243.8 138.4 519.5 372.4  
Segment assets 15,484.2   15,484.2   $ 14,392.2
New vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 3,292.7 3,396.3 6,303.7 6,644.4  
Cost of sales:          
Total cost of sales 3,142.1 3,212.9 6,008.6 6,286.1  
Used vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 2,011.4 1,985.0 3,975.2 3,907.4  
Cost of sales:          
Total cost of sales 1,896.3 1,859.6 3,738.7 3,657.5  
Parts and service          
Segment Reporting Information [Line Items]          
Revenues from external customers 1,263.0 1,221.1 2,483.9 2,385.1  
Cost of sales:          
Total cost of sales 655.9 622.5 1,283.4 1,218.8  
Other          
Segment Reporting Information [Line Items]          
Revenues from external customers 5.1 4.3 9.5 7.7  
Cost of sales:          
Total cost of sales 4.4 4.0 9.0 7.1  
AN Reportable Segments          
Segment Reporting Information [Line Items]          
Revenues from external customers 6,605.9 6,624.6 12,812.1 12,965.8  
AN Reportable Segment, Domestic          
Segment Reporting Information [Line Items]          
Revenues from external customers 1,793.1 1,920.5 3,509.7 3,637.9  
AN Reportable Segment, Domestic | New vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 890.8 985.1 1,717.6 1,845.3  
AN Reportable Segment, Domestic | Used vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 500.7 527.2 1,000.1 1,013.3  
AN Reportable Segment, Domestic | Parts and service          
Segment Reporting Information [Line Items]          
Revenues from external customers 291.0 289.3 573.0 558.3  
AN Reportable Segment, Domestic | Other          
Segment Reporting Information [Line Items]          
Revenues from external customers 0.9 0.4 1.7 0.7  
AN Reportable Segment, Import          
Segment Reporting Information [Line Items]          
Revenues from external customers 2,233.1 2,148.3 4,281.2 4,195.6  
AN Reportable Segment, Import | New vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 1,170.2 1,129.6 2,205.5 2,191.6  
AN Reportable Segment, Import | Used vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 578.5 549.6 1,132.5 1,096.3  
AN Reportable Segment, Import | Parts and service          
Segment Reporting Information [Line Items]          
Revenues from external customers 354.5 343.0 689.0 661.6  
AN Reportable Segment, Import | Other          
Segment Reporting Information [Line Items]          
Revenues from external customers 2.8 2.4 4.8 3.9  
AN Reportable Segment, Premium Luxury          
Segment Reporting Information [Line Items]          
Revenues from external customers 2,579.7 2,555.8 5,021.2 5,132.3  
AN Reportable Segment, Premium Luxury | New vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 1,231.7 1,281.6 2,380.6 2,607.5  
AN Reportable Segment, Premium Luxury | Used vehicle          
Segment Reporting Information [Line Items]          
Revenues from external customers 766.1 722.3 1,500.3 1,434.4  
AN Reportable Segment, Premium Luxury | Parts and service          
Segment Reporting Information [Line Items]          
Revenues from external customers 470.3 437.4 924.7 861.8  
AN Reportable Segment, Premium Luxury | Other          
Segment Reporting Information [Line Items]          
Revenues from external customers 0.2 0.2 0.6 0.2  
AN Reportable Segment, AN Finance          
AutoNation Finance:          
Interest and fee income 68.6 48.6 131.3 90.5  
Interest expense (27.1) (17.8) (51.5) (31.7)  
Provision for credit losses (20.1) (19.2) (39.6) (38.1)  
Direct expenses [1] (10.7) (9.6) (20.1) (18.6)  
AutoNation Finance income 10.7 2.0 20.1 2.1  
Operating Segments | AN Reportable Segment, Franchised Dealerships          
Selling, general and administrative expenses:          
Franchised dealerships - segment income 354.4 405.5 701.1 779.4  
Operating Segments | AN Reportable Segment, Domestic          
Segment Reporting Information [Line Items]          
Revenues from external customers 1,793.1 1,920.5 3,509.7 3,637.9  
Cost of sales:          
Total cost of sales 1,501.0 1,605.5 2,924.6 3,044.4  
Selling, general and administrative expenses:          
Compensation 123.6 132.5 245.7 252.3  
Advertising 18.9 16.7 37.0 33.4  
Store overhead 45.1 45.5 93.1 90.9  
Total selling, general, and administrative expenses 187.6 194.7 375.8 376.6  
Depreciation and amortization 11.4 11.5 22.6 22.5  
Floorplan interest expense 16.2 16.8 31.7 33.4  
Other loss (income) 2.9 [2]   2.9 [2] 0.0 [3]  
Franchised dealerships - segment income 74.0 92.0 152.1 161.0  
AutoNation Finance:          
Segment assets [4] 2,386.2   2,386.2   2,360.0
Operating Segments | AN Reportable Segment, Domestic | New vehicle          
Cost of sales:          
Total cost of sales 868.1 952.7 1,672.7 1,787.4  
Operating Segments | AN Reportable Segment, Domestic | Used vehicle          
Cost of sales:          
Total cost of sales 476.9 498.5 948.4 957.5  
Operating Segments | AN Reportable Segment, Domestic | Parts and service          
Cost of sales:          
Total cost of sales 155.7 154.2 302.8 299.5  
Operating Segments | AN Reportable Segment, Domestic | Other          
Cost of sales:          
Total cost of sales 0.3 0.1 0.7 0.0  
Operating Segments | AN Reportable Segment, Import          
Segment Reporting Information [Line Items]          
Revenues from external customers 2,233.1 2,148.3 4,281.2 4,195.6  
Cost of sales:          
Total cost of sales 1,845.7 1,756.8 3,526.4 3,433.7  
Selling, general and administrative expenses:          
Compensation 156.8 157.4 306.1 305.8  
Advertising 27.2 23.3 53.5 44.9  
Store overhead 56.7 55.1 112.6 108.6  
Total selling, general, and administrative expenses 240.7 235.8 472.2 459.3  
Depreciation and amortization 14.4 12.8 28.0 24.8  
Floorplan interest expense 8.8 9.5 17.3 18.2  
Other loss (income) 0.0 [2]   0.0 [2] 0.0 [3]  
Franchised dealerships - segment income 123.5 133.4 237.3 259.6  
AutoNation Finance:          
Segment assets [4] 2,261.0   2,261.0   2,209.3
Operating Segments | AN Reportable Segment, Import | New vehicle          
Cost of sales:          
Total cost of sales 1,113.4 1,067.8 2,099.8 2,072.6  
Operating Segments | AN Reportable Segment, Import | Used vehicle          
Cost of sales:          
Total cost of sales 542.3 513.5 1,059.1 1,023.6  
Operating Segments | AN Reportable Segment, Import | Parts and service          
Cost of sales:          
Total cost of sales 185.9 171.6 359.7 330.8  
Operating Segments | AN Reportable Segment, Import | Other          
Cost of sales:          
Total cost of sales 4.1 3.9 7.8 6.7  
Operating Segments | AN Reportable Segment, Premium Luxury          
Segment Reporting Information [Line Items]          
Revenues from external customers 2,579.7 2,555.8 5,021.2 5,132.3  
Cost of sales:          
Total cost of sales 2,118.0 2,078.3 4,104.2 4,180.3  
Selling, general and administrative expenses:          
Compensation 167.1 168.2 329.7 333.9  
Advertising 18.8 15.2 36.8 31.0  
Store overhead 79.7 76.2 161.9 151.7  
Total selling, general, and administrative expenses 265.6 259.6 528.4 516.6  
Depreciation and amortization 21.7 20.1 43.0 40.0  
Floorplan interest expense 17.3 17.7 33.7 36.7  
Other loss (income) 0.2 [2]   0.2 [2] (0.1) [3]  
Franchised dealerships - segment income 156.9 180.1 311.7 358.8  
AutoNation Finance:          
Segment assets [4] 3,903.9   3,903.9   3,611.2
Operating Segments | AN Reportable Segment, Premium Luxury | New vehicle          
Cost of sales:          
Total cost of sales 1,160.5 1,192.4 2,236.1 2,426.1  
Operating Segments | AN Reportable Segment, Premium Luxury | Used vehicle          
Cost of sales:          
Total cost of sales 730.9 679.8 1,426.0 1,348.8  
Operating Segments | AN Reportable Segment, Premium Luxury | Parts and service          
Cost of sales:          
Total cost of sales 226.4 205.9 441.6 405.3  
Operating Segments | AN Reportable Segment, Premium Luxury | Other          
Cost of sales:          
Total cost of sales 0.2 0.2 0.5 0.1  
Operating Segments | AN Reportable Segment, AN Finance          
AutoNation Finance:          
Interest and fee income 68.6 48.6 131.3 90.5  
Interest expense (27.1) (17.8) (51.5) (31.7)  
Provision for credit losses (20.1) (19.2) (39.6) (38.1)  
Direct expenses [1] (10.7) (9.6) (20.1) (18.6)  
AutoNation Finance income 10.7 2.0 20.1 2.1  
Segment assets [4] 2,686.9   2,686.9   $ 2,185.7
Corporate and other          
Segment Reporting Information [Line Items]          
Revenues from external customers $ 323.9 $ 349.8 $ 669.8 $ 699.0  
[1]
(1) Direct expenses are comprised primarily of compensation expense and loan administration costs incurred by our auto finance company.
[2]
(2) Other expense, net includes asset impairments net of gains on asset dispositions.
[3]
(2) Other income includes net gains on asset dispositions.
[4]
(1) Excludes capital expenditures for active construction projects, which are reflected in segment assets upon completion of the related project.