Interim Financial Statements (Details)	9 Months Ended
	Sep. 30, 2025 store franchises brand
Product Information [Line Items]
Owned and operated new vehicle franchises | franchises	323
Number of brands | brand	30
Percentage of new vehicle sales from core brands (percent)	89.00%
Dealerships
Product Information [Line Items]
Number of stores	244
Collision Centers
Product Information [Line Items]
Number of stores	52
AutoNation USA Stores
Product Information [Line Items]
Number of stores	26
Automotive Auction Operations
Product Information [Line Items]
Number of stores	4
Parts Distribution Centers
Product Information [Line Items]
Number of stores	3