Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended
	May 31, 2022	May 31, 2021
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	$ 9,311,621	$ 7,697,599
Depreciation and amortization	70,473	62,356
Gross Profit	875,391	924,509
CARMAX AUTO FINANCE INCOME	204,473	241,731
Selling, General and Administrative Expense	(656,740)	(554,069)
Depreciation, Depletion and Amortization, Nonproduction	(55,648)	(49,890)
Interest expense	(28,775)	(20,534)
Other expense (income)	(2,099)	25,577
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	336,602	$ 567,324
TOTAL COST OF SALES
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	3,386
Intersegment Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	(7,742)
Gross Profit	(1,626)
CarMax Sales Operations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	9,277,236
Gross Profit	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	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	9,277,236
Other Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
NET SALES AND OPERATING REVENUES	34,385
Gross Profit	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	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	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	$ 42,127