Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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 210.9-03.7(d))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph a(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

+ Details

Finance Receivables, Net (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2012	Mar. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	$ 64,519	$ 63,172
Allowance for credit losses	(501)	(527)	(606)	(619)
Finance receivables, net	63,911	62,567
Finance Receivables, Net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	64,519	63,172	60,475
Deferred origination costs	637	634
Unearned income	(821)	(794)
Allowance for credit losses	(424)	(445)	(515)	(524)
Finance receivables, net	63,911	62,567
Finance Receivables, Net [Member] \| Retail receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	40,001	40,508
Finance Receivables, Net [Member] \| Pledged retail receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	8,725	7,669
Finance Receivables, Net [Member] \| Dealer financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	15,793	14,995
Allowance for credit losses	(112)	(107)
Finance Receivables, Net [Member] \| Retail and Pledged Retail Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	(312)	(338)
Investments In Operating Leases, Net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ (77)	$ (82)