Auto Loan Receivables (Ending Managed Receivables By Major Credit Grade) (Details) - USD ($) $ in Millions	May 31, 2022	Feb. 28, 2022
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 2,384.1	$ 7,765.0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	6,927.4	3,596.9
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,184.7	2,453.3
Financing Receivable, Originated Three Years before Latest Fiscal Year	2,118.8	1,227.7
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,008.9	492.4
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	428.1	117.0
Financing Receivable, before Allowance for Credit Loss	$ 16,052.0	$ 15,652.3
Total ending managed receivables as percentage by major credit grade	100.00%	100.00%
Core managed receivables
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 2,302.9	$ 7,599.8
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	6,765.8	3,573.0
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,163.4	2,418.6
Financing Receivable, Originated Three Years before Latest Fiscal Year	2,088.2	1,203.9
Financing Receivable, Originated Four Years before Latest Fiscal Year	987.8	482.4
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	416.8	112.3
Financing Receivable, before Allowance for Credit Loss	$ 15,724.9	$ 15,390.0
Total ending managed receivables as percentage by major credit grade	98.00%	98.30%
Credit Grade A | Core managed receivables
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 1,192.3	$ 3,885.5
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	3,447.1	1,788.3
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,584.2	1,266.1
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,088.7	574.1
Financing Receivable, Originated Four Years before Latest Fiscal Year	463.0	203.4
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	158.3	32.3
Financing Receivable, before Allowance for Credit Loss	$ 7,933.6	$ 7,749.7
Total ending managed receivables as percentage by major credit grade	49.40%	49.50%
Credit Grade B | Core managed receivables
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 869.9	$ 2,795.2
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,495.0	1,288.5
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,139.0	857.7
Financing Receivable, Originated Three Years before Latest Fiscal Year	743.6	473.1
Financing Receivable, Originated Four Years before Latest Fiscal Year	393.8	205.2
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	183.0	50.4
Financing Receivable, before Allowance for Credit Loss	$ 5,824.3	$ 5,670.1
Total ending managed receivables as percentage by major credit grade	36.30%	36.20%
Credit Grade C And Other | Core managed receivables
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 240.7	$ 919.1
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	823.7	496.2
Financing Receivable, Originated Two Years before Latest Fiscal Year	440.2	294.8
Financing Receivable, Originated Three Years before Latest Fiscal Year	255.9	156.7
Financing Receivable, Originated Four Years before Latest Fiscal Year	131.0	73.8
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	75.5	29.6
Financing Receivable, before Allowance for Credit Loss	$ 1,967.0	$ 1,970.2
Total ending managed receivables as percentage by major credit grade	12.30%	12.60%
Credit Grade C And Other | Other managed receivables
Financing Receivable, By Major Credit Grade [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 81.2	$ 165.2
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	161.6	23.9
Financing Receivable, Originated Two Years before Latest Fiscal Year	21.3	34.7
Financing Receivable, Originated Three Years before Latest Fiscal Year	30.6	23.8
Financing Receivable, Originated Four Years before Latest Fiscal Year	21.1	10.0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	11.3	4.7
Financing Receivable, before Allowance for Credit Loss	$ 327.1	$ 262.3
Total ending managed receivables as percentage by major credit grade	2.00%	1.70%