CarMax Auto Finance (Components Of CarMax Auto Finance Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	May 31, 2023	May 31, 2022
Auto Finance Income [Line Items]
Interest and fee income	$ 400,500	$ 346,700
Interest expense	(142,600)	(48,800)
Total interest margin	257,900	297,900
Provision for loan losses	(80,900)	(57,800)
Total interest margin after provision for loan losses	177,000	240,100
Payroll and fringe benefit expense	(16,600)	(14,700)
Other Depreciation and Amortization	(4,100)	(3,800)
Other direct expenses	(18,900)	(17,100)
Total direct expenses	(39,600)	(35,600)
CarMax Auto Finance income	137,358	204,473
Total average managed receivables	$ 17,003,400	$ 15,817,000
Interest and fee income, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	9.40%	8.80%
Interest expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(3.40%)	(1.20%)
Total interest margin, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	6.10%	7.50%
Provision for loan losses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(1.90%)	(1.50%)
Total interest margin after provision for loan losses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	4.20%	6.10%
Payroll and fringe benefit expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.40%)	(0.40%)
Other Depreciation and Amortization
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.10%)	(0.10%)
Other direct expenses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.40%)	(0.40%)
Total direct expenses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.90%)	(0.90%)
CarMax Auto Finance income, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	3.20%	5.20%