Auto Loan Receivables (Allowance for Loan Losses) (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Nov. 30, 2024	Nov. 30, 2023	Nov. 30, 2024	Nov. 30, 2023	Feb. 29, 2024	Aug. 31, 2024	Aug. 31, 2023	Feb. 28, 2023
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 478,923,000	$ 511,900,000	$ 478,923,000	$ 511,900,000	$ 482,790,000	$ 500,800,000	$ 538,000,000.0	$ 507,200,000
Financing Receivable, Allowance for Credit Loss, Writeoff	(150,200,000)	(148,700,000)	(447,100,000)	(401,700,000)	$ (561,500,000)
Financing Receivable, Allowance for Credit Loss, Recovery	55,700,000	54,300,000	176,800,000	167,400,000
Provision for Loan, Lease, and Other Losses	$ 72,600,000	$ 68,300,000	266,400,000	$ 239,000,000.0
Item As Percent Of Total Ending Managed Receivables, Period Increase (Decrease)			$ 8
Allowance For Loan Losses, percent
Financing Receivable, Allowance for Credit Loss [Line Items]
Item as percent of total ending managed receivables	2.70%	2.92%	2.70%	2.92%	2.78%	2.82%	3.08%	3.02%
Core managed receivables
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 398,700,000	$ 412,400,000	$ 398,700,000	$ 412,400,000	$ 389,700,000	$ 417,300,000	$ 433,000,000.0	$ 401,500,000
Financing Receivable, Allowance for Credit Loss, Writeoff	(129,000,000.0)	(125,100,000)	(373,100,000)	(336,900,000)
Financing Receivable, Allowance for Credit Loss, Recovery	48,700,000	47,200,000	154,700,000	146,200,000
Provision for Loan, Lease, and Other Losses	61,700,000	57,300,000	227,400,000	201,600,000
Other managed receivables
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	80,200,000	99,500,000	80,200,000	99,500,000	$ 93,100,000	$ 83,500,000	$ 105,000,000.0	$ 105,700,000
Financing Receivable, Allowance for Credit Loss, Writeoff	(21,200,000)	(23,600,000)	(74,000,000.0)	(64,800,000)
Financing Receivable, Allowance for Credit Loss, Recovery	7,000,000.0	7,100,000	22,100,000	21,200,000
Provision for Loan, Lease, and Other Losses	$ 10,900,000	$ 11,000,000.0	$ 39,000,000.0	$ 37,400,000