Variable Interest Entities - Summary of Assets and Liabilities of Consolidated Secured Financing VIEs (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Cash	$ 545	$ 197
Receivables, net	28,544	29,284
Available-for-sale investments	0	80
Long-term debt	27,555	28,426
Variable Interest Entity [Member]
Variable Interest Entity [Line Items]
Cash	3	6
Receivables, net	4,088	4,197
Available-for-sale investments		0
Subtotal, Consolidated Assets	4,091	4,203
Other liabilities	(44)	(39)
Long-term debt	2,759	2,878
Subtotal, Consolidated Liabilities	$ 2,715	$ 2,839

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References+ Details

- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References+ Details

- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References+ Details