CarMax Auto Finance (Components Of CarMax Auto Finance Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	May 31, 2021	May 31, 2020
Auto Finance Income [Line Items]
Interest and fee income	$ 310,300	$ 282,500
Interest expense	(65,800)	(84,600)
Total interest margin	244,500	197,900
Provision for loan losses	24,400	(122,000)
Total interest margin after provision for loan losses	268,900	75,900
Total other expense	0	(1,900)
Payroll and fringe benefit expense	(12,600)	(11,200)
Other Depreciation and Amortization	(200)	(200)
Other direct expenses	(14,400)	(11,600)
Total direct expenses	(27,200)	(23,000)
CarMax Auto Finance income	241,731	50,950
Total average managed receivables	$ 14,148,700	$ 13,408,500
Interest and fee income, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	8.80%	8.40%
Interest expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(1.90%)	(2.50%)
Total interest margin, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	6.90%	5.90%
Provision for loan losses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	0.70%	(3.60%)
Total interest margin after provision for loan losses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	7.60%	2.30%
Total other expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	0.00%	(0.10%)
Payroll and fringe benefit expense, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.40%)	(0.30%)
Other Depreciation and Amortization
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	0.00%	0.00%
Other direct expenses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.40%)	(0.30%)
Total direct expenses, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	(0.80%)	(0.70%)
CarMax Auto Finance income, percent
Auto Finance Income [Line Items]
Item as percent of total average managed receivables	6.80%	1.50%