Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended
	May 31, 2023	May 31, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 7,687,063	$ 9,311,621
Depreciation and amortization	62,998	70,473
Gross Profit	817,390	875,391
CARMAX AUTO FINANCE INCOME	137,358	204,473
Selling, General and Administrative Expense	(559,837)	(656,740)
Depreciation, Depletion and Amortization, Nonproduction	(58,419)	(55,648)
Interest expense	(30,466)	(28,775)
Other (income) expense	1,214	(2,099)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	307,240	336,602
TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	4,811	3,386
Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	(9,597)	(7,742)
Gross Profit	(1,174)	(1,626)
CarMax Sales Operations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	7,655,689	9,277,236
Gross Profit	794,391	849,290
CarMax Sales Operations | TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	419	312
CarMax Sales Operations | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	7,655,689	9,277,236
Other Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	31,374	34,385
Gross Profit	24,173	27,727
Other Segments | TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	4,392	3,074
Other Segments | Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	9,597	7,742
Other Segments | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 40,971	$ 42,127