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Auto Loan Receivables (Ending Managed Receivables By Major Credit Grade) (Details) - USD ($) $ in Millions	May 31, 2018	Feb. 28, 2018
Financing Receivable, By Major Credit Grade [Line Items]
Total ending managed receivables	$ 11,925.0	$ 11,618.9
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]
Total ending managed receivables	$ 5,871.2	$ 5,725.1
Total ending managed receivables as percentage by major credit grade	49.20%	49.30%
Credit Grade B
Financing Receivable, By Major Credit Grade [Line Items]
Total ending managed receivables	$ 4,267.2	$ 4,133.8
Total ending managed receivables as percentage by major credit grade	35.80%	35.60%
Credit Grade C And Other
Financing Receivable, By Major Credit Grade [Line Items]
Total ending managed receivables	$ 1,786.6	$ 1,760.0
Total ending managed receivables as percentage by major credit grade	15.00%	15.10%

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Total ending managed receivables as percentage by major credit grade.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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