CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounts and notes receivable, allowance for doubtful accounts	$ 62	$ 68
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	25,000,000	25,000,000
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	6,000,000,000	6,000,000,000
Common stock, issued (in shares)	2,020,000,000	2,107,000,000
Common stock, outstanding (in shares)	2,020,000,000	2,107,000,000