Accumulated Other Comprehensive Loss (Changes In and Reclassifications Out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 28, 2018
Actuarial loss arising during the year	$ (68,861)	$ (4,560)	$ (3,256)
Tax benefit	16,607	1,101	710
Actuarial loss arising during the year, net of tax	(52,254)	(3,459)	(2,546)
Actuarial loss amortization reclassifications in net pension expense	1,874	1,949	1,815
Tax expense	(444)	(471)	(640)
Amortization reclassifications recognized in net pension expense, net of tax	1,430	1,478	1,175
Net change in retirement benefit plan unrecognized actuarial losses, net of tax	(50,824)	(1,981)	(1,371)
Changes in fair value	(47,083)	(9,103)	17,953
Tax benefit (loss)	12,452	2,400	(5,572)
Changes in fair value, net of tax	(34,631)	(6,703)	12,381
Reclassifications to CarMax Auto Finance income	4,614	(6,809)	3,009
Tax (expense) benefit	(1,220)	1,795	(1,196)
Reclassification of hedge losses (gains), net of tax	3,394	(5,014)	1,813
Net change in cash flow hedge unrecognized losses, net of tax	(31,237)	(11,717)	14,194
Total other comprehensive (loss) income, net of tax	(82,061)	(13,698)	12,823
TOTAL COST OF SALES
Actuarial loss amortization reclassifications in net pension expense	797	812	749
CarMax Auto Finance income
Actuarial loss amortization reclassifications in net pension expense	49	51	46
Selling, general and administrative expenses
Actuarial loss amortization reclassifications in net pension expense	$ 1,028	$ 1,086	$ 1,020