Consolidated Balance Sheets Parentheticals - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Consolidated Balance Sheets Parenthetical [Abstract]
Receivables, less reserve of $11 and $11	$ 11	$ 11
Less accumulated depreciation, depletion and amortization	$ (18,003)	$ (21,830)
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares authorized	26,000,000	26,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 1	$ 1
Common stock, shares authorized	1,925,000,000	1,925,000,000
Common stock, shares issued	937,000,000	937,000,000
Held in treasury, shares	141,000,000	118,000,000