Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Current Assets:
Allowance for uncollectible accounts	$ 23	$ 23
Allowance for obsolescence	126	136
Noncurrent Assets:
Accumulated depreciation and amortization	20,655	20,370
Accumulated amortization	$ 906	$ 902
Stockholders' Equity:
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001
Common stock, authorized (shares)	1,500,000,000	1,500,000,000
Common stock, issued (shares)	654,572,361	651,800,786
Treasury stock, at cost (shares)	11,153,986	10,535,033