Derivatives and Other Financial Instruments - Schedule of Carrying Values and Fair Values of Other Financial Instruments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Cash and Cash Equivalents [Member]
Derivative [Line Items]
Carrying value	$ 1,437	$ 1,861
Fair value	1,437	1,861
Restricted Cash [Member]
Derivative [Line Items]
Carrying value	18	189
Fair value	18	189
Noncurrent Receivables [Member]
Derivative [Line Items]
Carrying value	19	20
Fair value	19	20
Available-for-Sale Securities [Member]
Derivative [Line Items]
Carrying value	119	67
Fair value	119	67
Short-Term Borrowings [Member]
Derivative [Line Items]
Carrying value	57	53
Fair value	57	53
Commercial Paper [Member]
Derivative [Line Items]
Carrying value
Fair value
Long-Term Debt Due within One Year [Member]
Derivative [Line Items]
Carrying value	655	465
Fair value	1,040	477
Long-Term Debt, Less Amount Due within One Year [Member]
Derivative [Line Items]
Carrying value	7,607	8,311
Fair value	$ 7,863	$ 9,028