Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2023	Aug. 31, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 7,073,836	$ 8,144,803	$ 14,760,899	$ 17,456,424
Depreciation and amortization			126,971	137,903
Gross Profit	696,765	737,145	1,514,155	1,612,536
CARMAX AUTO FINANCE INCOME	134,987	182,869	272,345	387,342
Selling, General and Administrative Expense	(585,694)	(666,041)	(1,145,531)	(1,322,781)
Depreciation, Depletion and Amortization, Nonproduction	(58,817)	(57,692)	(117,236)	(113,340)
Interest expense	(31,585)	(32,745)	(62,051)	(61,520)
Other income	2,630	4,039	3,844	1,940
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	158,286	167,575	465,526	504,177
TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	5,173	3,765	9,984	7,151
Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	(8,468)	(6,929)	(18,064)	(14,670)
Gross Profit	(1,126)	(1,501)	(2,300)	(3,127)
CarMax Sales Operations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	7,040,330	8,110,524	14,696,019	17,387,760
Gross Profit	672,505	712,284	1,466,896	1,561,573
CarMax Sales Operations | TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	427	376	846	688
CarMax Sales Operations | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	7,040,330	8,110,524	14,696,019	17,387,760
Other Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	33,506	34,279	64,880	68,664
Gross Profit	25,386	26,362	49,559	54,090
Other Segments | TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	4,746	3,389	9,138	6,463
Other Segments | Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	8,468	6,929	18,064	14,670
Other Segments | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 41,974	$ 41,208	$ 82,944	$ 83,334