CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
OPERATING ACTIVITIES
Net income	$ 1,525	$ 1,057
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	3,142	3,515
Deferred income taxes	431	315
Provision for uncollectible accounts	80	137
Net (gain) loss on early retirement of debt	(8)	78
Share-based compensation	89	120
Changes in current assets and liabilities:
Accounts receivable	20	(34)
Accounts payable	(240)	(325)
Accrued income and other taxes	7	90
Other current assets and liabilities, net	(263)	(408)
Retirement benefits	(126)	(96)
Changes in other noncurrent assets and liabilities, net	207	287
Other, net	30	106
Net cash provided by operating activities	4,894	4,842
INVESTING ACTIVITIES
Capital expenditures	(2,052)	(2,971)
Proceeds from sale of property, plant and equipment and other assets	90	119
Other, net	13	12
Net cash used in investing activities	(1,949)	(2,840)
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	1,881	3,257
Payments of long-term debt	(2,604)	(6,334)
Net (payments of) proceeds from revolving line of credit	(150)	825
Dividends paid	(834)	(837)
Repurchases of common stock	(909)	0
Other, net	(52)	(83)
Net cash used in financing activities	(2,668)	(3,172)
Net increase (decrease) in cash, cash equivalents and restricted cash	277	(1,170)
Cash, cash equivalents and restricted cash at beginning of period	427	1,717
Cash, cash equivalents and restricted cash at end of period	704	547
Supplemental cash flow information:
Income taxes (paid) refunded, net	(102)	51
Interest paid (net of capitalized interest of $39 and $60)	(1,144)	(1,254)
Supplemental noncash information regarding investing activities:
Sale of property, plant and equipment in exchange for note receivable	56	0
Cash, cash equivalents and restricted cash:
Cash and cash equivalents	635	526
Cash and cash equivalents included in Assets held for sale	39	0
Restricted cash included in Other current assets	2	3
Restricted cash included in Other, net noncurrent assets	28	18
Total	$ 704	$ 547