CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
OPERATING REVENUE	$ 3,290	$ 3,738
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	1,652	1,817
Selling, general and administrative	823	721
Loss on sale of business	22	77
Depreciation and amortization	748	733
Total operating expenses	3,245	3,348
OPERATING INCOME	45	390
OTHER INCOME (EXPENSE)
Interest expense	(291)	(279)
Net gain on early retirement of debt (Note 5)	275	609
Other income (expense), net	73	(40)
Total other income, net	57	290
INCOME BEFORE INCOME TAXES	102	680
Income tax expense	45	169
NET INCOME	$ 57	$ 511
Earnings Per Share [Abstract]
BASIC (in dollars per share)	$ 0.06	$ 0.52
DILUTED (in dollars per share)	$ 0.06	$ 0.52
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
BASIC (in shares)	984,855	981,555
DILUTED (in shares)	986,262	982,283