Income Taxes - Components of Total Deferred Taxes Table (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred Tax Assets (Liabilities), Net [Line Items]
Total deferred taxes	$ (8,885)	$ (8,431)
Federal [Member]
Deferred Tax Assets (Liabilities), Net [Line Items]
Total deferred taxes	(8,246)	(7,890)
State, net of federal [Member]
Deferred Tax Assets (Liabilities), Net [Line Items]
Total deferred taxes	(332)	(325)
Foreign [Member]
Deferred Tax Assets (Liabilities), Net [Line Items]
Total deferred taxes	$ (307)	$ (216)