CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Statement Of Financial Position [Abstract]
Property and equipment, accumulated depreciation	$ 3,759	$ 3,710
Common shares, par value	$ 1.25	$ 1.25
Common shares, authorized	1,360,000,000	1,360,000,000
Common shares, issued	732,507,000	732,794,000
Common shares, outstanding	732,507,000	732,794,000