Accumulated Other Comprehensive Loss (Changes In and Reclassifications Out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019
Total amortization reclassifications recognized in net pension expense	$ 960	$ 469	$ 1,919	$ 937
Tax expense	(232)	(113)	(463)	(226)
Amortization reclassifications recognized in net pension expense, net of tax	728	356	1,456	711
Net change in retirement benefit plan unrecognized actuarial losses, net of tax	728	356	1,456	711
Changes in fair value	79	(15,431)	(24,783)	(33,373)
Tax (expense) benefit	(21)	4,077	6,554	8,819
Changes in fair value, net of tax	58	(11,354)	(18,229)	(24,554)
Reclassifications to CarMax Auto Finance income	5,701	780	8,726	303
Tax expense	(1,508)	(206)	(2,308)	(80)
Reclassification of hedge losses, net of tax	4,193	574	6,418	223
Net change in cash flow hedge unrecognized losses, net of tax	4,251	(10,780)	(11,811)	(24,331)
Total other comprehensive income (loss), net of tax	4,979	(10,424)	(10,355)	(23,620)
Cost of sales
Total amortization reclassifications recognized in net pension expense	437	201	810	398
CarMax Auto Finance income
Total amortization reclassifications recognized in net pension expense	25	12	56	24
Selling, general and administrative expenses
Total amortization reclassifications recognized in net pension expense	$ 498	$ 256	$ 1,053	$ 515