CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
OPERATING ACTIVITIES
Net income	$ 511	$ 599
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	733	808
Loss on disposal group held for sale	77	0
Deferred income taxes	46	179
Provision for uncollectible accounts	27	25
Net gain on early retirement of debt	(609)	0
Unrealized loss (gain) on investments	80	(66)
Stock-based compensation	14	23
Changes in current assets and liabilities:
Accounts receivable	14	131
Accounts payable	(8)	(38)
Accrued income and other taxes	143	34
Other current assets and liabilities, net	(374)	(376)
Retirement benefits	(15)	(38)
Changes in other noncurrent assets and liabilities, net	(16)	39
Other, net	(28)	55
Net cash provided by operating activities	595	1,375
INVESTING ACTIVITIES
Capital expenditures	(640)	(577)
Proceeds from sale of property, plant and equipment, and other assets	23	6
Other, net	1	2
Net cash used in investing activities	(616)	(569)
FINANCING ACTIVITIES
Payments of long-term debt	(61)	(1,474)
Net payments on revolving line of credit	0	1,000
Dividends paid	(8)	(271)
Other, net	(17)	(31)
Net cash used in financing activities	(86)	(776)
Net (decrease) increase in cash, cash equivalents and restricted cash	(107)	30
Cash, cash equivalents and restricted cash at beginning of period	1,307	409	$ 409
Cash, cash equivalents and restricted cash at end of period	1,200	439	1,307
Supplemental cash flow information:
Income taxes paid, net	(96)	(10)
Interest paid (net of capitalized interest of $21 and $16)	(363)	(386)
Supplemental noncash information regarding financing activities:
Cancellation of senior unsecured notes as part of exchange offers (Note 6)	(1,535)	0
Issuance of senior secured notes as part of exchange offers (Note 6)	915	0
Cash, cash equivalents and restricted cash:
Cash and cash equivalents	1,148	366	1,251
Cash and cash equivalents and restricted cash included in Assets held for sale	41	59
Restricted cash included in Other current assets	0	2
Restricted cash included in Other, net noncurrent assets	11	12
Total	$ 1,200	$ 439	$ 1,307