Schedule of Securitized Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Variable Interest Entity [Line Items]
Total assets	$ 108,045	$ 113,312
Securitized assets not required to be consolidated
Variable Interest Entity [Line Items]
Total assets	147	151
Securitized assets required to be consolidated
Variable Interest Entity [Line Items]
Total assets	314	424
Total securitized assets
Variable Interest Entity [Line Items]
Total assets	461	575
Other assets | Securitized assets not required to be consolidated
Variable Interest Entity [Line Items]
Total assets	$ 147	$ 151