CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Receivables, discounts and allowances	$ 1	$ 1
Property and equipment, accumulated depreciation	$ 3,376	$ 3,338
Common shares, par value	$ 1.25	$ 1.25
Common shares, authorized	1,360,000,000	1,360,000,000
Common shares, issued	746,390,932	755,222,727
Common shares, outstanding	746,390,932	755,222,727