Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for accounts and notes receivable, current	$ 313	$ 59
Preferred stock, par value (usd per share)	$ 1.00	$ 1.00
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Common stock, par value (usd per share)	$ 0.75	$ 0.75
Common stock, shares authorized	6,000,000,000	6,000,000,000
Common stock, shares issued	2,442,676,580	2,442,676,580
Treasury stock, shares	559,862,580	563,027,772