CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
CONDENSED CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts	$ 26	$ 26
Allowance for other receivables	5	7
Accumulated depreciation and amortization	$ 22,027	$ 21,627
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, shares issued	630,282,461	630,282,461
Treasury stock, shares	223,491,127	222,396,166