Auto Loans Held for Investment (Allowance for Loan Losses) (Details) - USD ($)	3 Months Ended		12 Months Ended
	May 31, 2025	May 31, 2024	Feb. 28, 2025	Feb. 29, 2024
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 474,222,000	$ 493,100,000	$ 458,730,000	$ 482,800,000
Financing Receivable, Allowance for Credit Loss, Writeoff	(141,700,000)	(133,100,000)	$ (589,200,000)
Financing Receivable, Allowance for Credit Loss, Recovery	55,500,000	62,200,000
Provision for Loan, Lease, and Other Losses	101,707,000	$ 81,226,000
Item As Percent Of Total Ending Managed Receivables, Period Increase (Decrease)	15
Transfer of auto loans held for sale
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for Loan, Lease, and Other Losses	(26,500,000)
Auto loans held for investment
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for Loan, Lease, and Other Losses	$ 128,200,000
Allowance For Loan Losses, percent
Financing Receivable, Allowance for Credit Loss [Line Items]
Item as percent of total ending managed receivables	2.76%	2.79%	2.61%	2.78%
Tier 1
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 395,800,000	$ 396,600,000	$ 378,100,000	$ 389,700,000
Financing Receivable, Allowance for Credit Loss, Writeoff	(120,200,000)	(113,000,000.0)
Financing Receivable, Allowance for Credit Loss, Recovery	48,800,000	53,900,000
Provision for Loan, Lease, and Other Losses		66,000,000.0
Tier 1 | Transfer of auto loans held for sale
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for Loan, Lease, and Other Losses	(19,100,000)
Tier 1 | Auto loans held for investment
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for Loan, Lease, and Other Losses	108,200,000
Tier 2 & Tier 3
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	78,400,000	96,500,000	$ 80,600,000	$ 93,100,000
Financing Receivable, Allowance for Credit Loss, Writeoff	(21,500,000)	(20,100,000)
Financing Receivable, Allowance for Credit Loss, Recovery	6,700,000	8,300,000
Provision for Loan, Lease, and Other Losses		$ 15,200,000
Tier 2 & Tier 3 | Transfer of auto loans held for sale
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for Loan, Lease, and Other Losses	(7,400,000)
Tier 2 & Tier 3 | Auto loans held for investment
Financing Receivable, Allowance for Credit Loss [Line Items]
Provision for Loan, Lease, and Other Losses	$ 20,000,000.0