Auto Loan Receivables (Allowance for Loan Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2023	Aug. 31, 2022	May 31, 2023	Feb. 28, 2023	May 31, 2022	Feb. 28, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 538,018	$ 477,500	$ 538,018	$ 477,500	$ 535,400	$ 507,201	$ 458,200	$ 433,000
Financing Receivable, Allowance for Credit Loss, Writeoff	(143,200)	(96,100)	(253,000)	(164,300)
Financing Receivable, Allowance for Credit Loss, Recovery	56,000	39,900	113,100	75,500
Provision for loan losses	$ 89,800	$ 75,500	170,700	$ 133,300
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)			$ 30,800
Allowance For Loan Losses, percent
Financing Receivable, Allowance for Credit Loss [Line Items]
Item as percent of total ending managed receivables	3.08%	2.92%	3.08%	2.92%	3.11%	3.02%	2.85%	2.77%
Core managed receivables
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	$ 433,000	$ 396,100	$ 433,000	$ 396,100	$ 427,500	$ 401,500	$ 390,400	$ 377,500
Financing Receivable, Allowance for Credit Loss, Writeoff	(118,700)	(84,200)	(211,800)	(145,600)
Financing Receivable, Allowance for Credit Loss, Recovery	48,500	35,900	99,000	69,000
Provision for loan losses	75,700	54,000	144,300	95,200
Other managed receivables
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Allowance for Credit Loss	105,000	81,400	105,000	81,400	$ 107,900	$ 105,700	$ 67,800	$ 55,500
Financing Receivable, Allowance for Credit Loss, Writeoff	(24,500)	(11,900)	(41,200)	(18,700)
Financing Receivable, Allowance for Credit Loss, Recovery	7,500	4,000	14,100	6,500
Provision for loan losses	$ 14,100	$ 21,500	$ 26,400	$ 38,100