Receivables - Nonaccrual Receivables (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Nonaccrual receivables:
Total nonaccrual receivables	$ 5,305		$ 5,193
Real Estate Secured [Member]
Nonaccrual receivables:
Nonaccrual real estate secured receivables carried at lower amortized cost or fair value	642		1,700
Real estate secured [Member]
Nonaccrual receivables:
Total nonaccrual receivables	1,579	[1]	3,032	[1]
Nonaccrual receivables held for sale [Member]
Nonaccrual receivables:
Total nonaccrual receivables	$ 3,726		$ 2,161

[1] At June 30, 2013 and December 31, 2012, nonaccrual real estate secured receivables held for investment include $642 million and $1.7 billion, respectively, of receivables that are carried at the lower of amortized cost or fair value of the collateral less cost to sell.