Stock and Stock-Based Incentive Plans (Composition of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2025	Aug. 31, 2024	Aug. 31, 2025	Aug. 31, 2024
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	$ 24,813	$ 35,221	$ 72,472	$ 84,016
Cost of sales
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	1,222	1,639	1,869	2,648
Carmax Auto Finance Income
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	1,146	1,449	2,556	2,134
Selling, general and administrative expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	$ 22,445	$ 32,133	$ 68,047	$ 79,234