Consolidated Balance Sheets Parentheticals (USD $) In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Consolidated Balance Sheets Parenthetical [Abstract]
Less accumulated depreciation, depletion and amortization	$ (21,884)	$ (21,895)
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares authorized	26	26
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 1	$ 1
Common stock, shares authorized	1,100	1,100
Common stock, shares issued	770	770
Common stock, securities exchangeable no par value	$ 0	$ 0
Common stock, securities exchangeable shares authorized	29	29
Common stock, securities exchangeable shares issued	0	0
Common stock, securities exchangeable shares outstanding	0	0
Held in treasury, shares	95	73
Allowance for Doubtful Accounts Receivable, Current	$ 3	$ 0