Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2022	Aug. 31, 2021
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 8,144,803	$ 7,988,359	$ 17,456,424	$ 15,685,958
Depreciation and amortization			137,903	129,300
Gross Profit	737,145	815,484	1,612,536	1,739,993
CARMAX AUTO FINANCE INCOME	182,869	200,033	387,342	441,764
Selling, General and Administrative Expense	(666,041)	(574,286)	(1,322,781)	(1,128,355)
Depreciation, Depletion and Amortization, Nonproduction	(57,692)	(52,789)	(113,340)	(102,679)
Interest expense	(32,745)	(22,410)	(61,520)	(42,944)
Other income	4,039	1,782	1,940	27,359
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	167,575	$ 367,814	504,177	$ 935,138
TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	3,765		7,151
Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	(6,929)		(14,670)
Gross Profit	(1,501)		(3,127)
CarMax Sales Operations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	8,110,524		17,387,760
Gross Profit	712,284		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	376		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	8,110,524		17,387,760
Other Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	34,279		68,664
Gross Profit	26,362		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	3,389		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	6,929		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	$ 41,208		$ 83,334