Shareholders' Equity (Shares Issued And Shares Surrendered To Satisfy Tax Withholdings In Connection With Restricted Stock Units) (Details) - Restricted Stock Units (RSUs) [Member] - shares shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)	0.6	0.8	0.7
Shares surrendered to AutoNation to satisfy tax withholding obligations (in shares)	0.2	0.3	0.2