Auto Loan Receivables (Ending Managed Receivables By Major Credit Grade) (Details) - USD ($) $ in Millions	Nov. 30, 2021	Feb. 28, 2021
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 6,401.1	$ 5,561.7
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	4,028.5	4,112.6
Financing Receivable, Originated Two Years before Latest Fiscal Year	2,806.7	2,337.2
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,460.3	1,226.9
Financing Receivable, Originated Four Years before Latest Fiscal Year	639.1	494.9
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	188.3	113.9
Total ending managed receivables	$ 15,524.0	$ 13,847.2
Total ending managed receivables as percentage by major credit grade	100.00%	100.00%
Credit Grade A
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 3,172.3	$ 2,782.0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,999.2	2,146.5
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,454.6	1,146.7
Financing Receivable, Originated Three Years before Latest Fiscal Year	693.7	568.9
Financing Receivable, Originated Four Years before Latest Fiscal Year	275.2	199.6
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	57.6	30.4
Total ending managed receivables	$ 7,652.6	$ 6,874.1
Total ending managed receivables as percentage by major credit grade	49.30%	49.60%
Credit Grade B
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 2,306.4	$ 1,993.6
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,446.1	1,424.5
Financing Receivable, Originated Two Years before Latest Fiscal Year	977.3	870.1
Financing Receivable, Originated Three Years before Latest Fiscal Year	556.2	476.0
Financing Receivable, Originated Four Years before Latest Fiscal Year	260.0	195.5
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	80.4	49.2
Total ending managed receivables	$ 5,626.4	$ 5,008.9
Total ending managed receivables as percentage by major credit grade	36.20%	36.20%
Credit Grade C And Other
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 922.4	$ 786.1
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	583.2	541.6
Financing Receivable, Originated Two Years before Latest Fiscal Year	374.8	320.4
Financing Receivable, Originated Three Years before Latest Fiscal Year	210.4	182.0
Financing Receivable, Originated Four Years before Latest Fiscal Year	103.9	99.8
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	50.3	34.3
Total ending managed receivables	$ 2,245.0	$ 1,964.2
Total ending managed receivables as percentage by major credit grade	14.50%	14.20%

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