Segment Reporting (Details) - USD ($) $ in Thousands	12 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 29, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 31,900,412	$ 18,950,149	$ 20,319,987
Depreciation and amortization	273,188	242,156	215,811
Gross Profit	3,287,542	2,379,125	2,722,340
CARMAX AUTO FINANCE INCOME	801,507	562,810	456,030
Selling, General and Administrative Expense	(2,325,220)	(1,704,419)	(1,750,168)
Depreciation, Depletion and Amortization, Nonproduction	(211,956)	(194,356)	(189,899)
Interest expense	(94,095)	(86,178)	(83,007)
Nonoperating Income (Expense)	34,568	8,275	5,690
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	1,492,346	$ 965,257	$ 1,160,986
TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	8,332
Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	(22,169)
Gross Profit	(5,207)
CarMax Sales Operations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	31,798,596
Gross Profit	3,207,946
CarMax Sales Operations | TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	840
CarMax Sales Operations | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	31,798,596
Other Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	101,816
Gross Profit	84,803
Other Segments | TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	7,492
Other Segments | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	123,985
Other Segments | Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 22,169