Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 6,506.0	$ 8,527.8	$ 23,962.4	$ 24,213.7
Used vehicle sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,204.6	6,435.6	18,503.2	18,697.3
Wholesale vehicle sales
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,152.2	1,922.3	4,959.1	4,998.2
Extended protection plan revenues
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	91.8	106.6	318.1	353.8
Third-party finance income/(fees), net
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1.0	1.6	7.1	(0.3)
Advertising & subscription revenues [Domain]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	33.3	33.3	101.9	67.9
Service revenues
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	19.6	19.7	60.8	62.9
Other
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	3.5	8.7	12.3	33.9
Total other sales and revenues
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 149.2	$ 169.9	$ 500.2	$ 518.2