CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Statement [Abstract]
OPERATING REVENUE	$ 3,661	$ 4,612	$ 7,399	$ 9,288
OPERATING EXPENSES
Cost of services and products (exclusive of depreciation and amortization)	1,740	2,058	3,557	4,043
Selling, general and administrative	790	815	1,511	1,615
Loss on disposal group held for sale	13	0	90	0
Depreciation and amortization	746	827	1,479	1,635
Goodwill impairment	8,793	0	8,793	0
Total operating expenses	12,082	3,700	15,430	7,293
OPERATING (LOSS) INCOME	(8,421)	912	(8,031)	1,995
OTHER (EXPENSE) INCOME
Interest expense	(294)	(337)	(573)	(689)
Net gain on early retirement of debt (Note 6)	9	0	618	0
Other income (expense), net	16	(122)	(24)	(52)
Total other (expense) income, net	(269)	(459)	21	(741)
(LOSS) INCOME BEFORE INCOME TAXES	(8,690)	453	(8,010)	1,254
Income tax expense	46	109	215	311
NET (LOSS) INCOME	$ (8,736)	$ 344	$ (8,225)	$ 943
BASIC AND DILUTED (LOSS) EARNINGS PER COMMON SHARE
BASIC (in dollars per share)	$ (8.88)	$ 0.34	$ (8.37)	$ 0.93
DILUTED (in dollars per share)	$ (8.88)	$ 0.34	$ (8.37)	$ 0.93
WEIGHTED-AVERAGE COMMON SHARES OUTSTANDING
BASIC (in shares)	983,453	1,012,943	982,505	1,010,686
DILUTED (in shares)	983,453	1,016,620	982,505	1,015,917