Auto Loan Receivables (Past Due Receivables) (Details) - USD ($) $ in Millions	Nov. 30, 2019	Feb. 28, 2019
Financing Receivable, Past Due [Line Items]
Total ending managed receivables	$ 13,352.6	$ 12,510.2
Total past due	$ 510.9	$ 451.8
Past due receivables as a percentage of total ending managed receivables	3.80%	3.60%
Total ending managed receivables, percent
Financing Receivable, Past Due [Line Items]
Item as percent of total ending managed receivables	100.00%	100.00%
Thirty One To Sixty Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total past due	$ 323.0	$ 276.5
Past due receivables as a percentage of total ending managed receivables	2.40%	2.20%
Sixty One To Ninety Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total past due	$ 152.3	$ 141.4
Past due receivables as a percentage of total ending managed receivables	1.10%	1.10%
Greater Than Ninety Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total past due	$ 35.6	$ 33.9
Past due receivables as a percentage of total ending managed receivables	0.30%	0.30%