Auto Loan Receivables (Past Due Receivables) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended				12 Months Ended
	Aug. 31, 2012		Aug. 31, 2011		Feb. 29, 2012		Feb. 28, 2011
Financing Receivable, Past Due [Line Items]
Total ending managed receivables	$ 5,342.1	[1]	$ 4,707.7	[1]	$ 4,981.8	[1]	$ 4,334.6	[1]
31-60 days past due	103.9		95.4		85.1		86.6
61-90 days past due	31.3		27.5		21.8		24.2
Greater than 90 days past due	10.5		10.7		9.6		10.5
Total past due	$ 145.7		$ 133.6		$ 116.5		$ 121.3
Past due receivables as a percentage of total ending managed receivables	2.70%	[2]	2.80%	[2]	2.30%	[2]	2.80%	[2]
31-60 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past due receivables as a percentage of total ending managed receivables	1.90%	[2]	2.00%	[2]	1.70%	[2]	2.00%	[2]
61-90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past due receivables as a percentage of total ending managed receivables	0.60%	[2]	0.60%	[2]	0.40%	[2]	0.60%	[2]
Greater Than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past due receivables as a percentage of total ending managed receivables	0.20%	[2]	0.20%	[2]	0.20%	[2]	0.20%	[2]
Managed Receivables [Member]
Financing Receivable, Past Due [Line Items]
Item as percent of total ending managed receivables	100.00%	[2]	100.00%	[2]	100.00%	[2]	100.00%	[2]

[1] Classified based on credit grade assigned when customers were initially approved for financing.

[2] Percent of total ending managed receivables.