Stock and Stock-Based Incentive Plans (Composition of Share-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	May 31, 2022	May 31, 2021
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	$ 23,184	$ 41,857
Cost of sales
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	240	1,729
Carmax Auto Finance Income
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	708	1,708
Selling, general and administrative expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense, before income taxes	$ 22,236	$ 38,420