Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows provided from (used by) operating activities:
Net Income	$ 12	$ 286
Adjustments to reconcile net income to net cash provided from (used by) operating activities:
Depreciation and amortization	1,040	870
Pension settlement costs		50
Stock-based compensation expense	81	54
Lease Impairment		44
Amortization of premium	(21)	(21)
Bad debt expense	24	19
Other adjustments	9	1
Deferred income taxes	(1)	167
Change in accounts receivable	(35)	16
Change in long-term pension and other postretirement liabilities	(149)	(527)
Change in accounts payable and other liabilities	101	94
Change in prepaid expenses, income taxes, and other assets	(13)	(12)
Net cash provided from operating activities	1,048	1,041
Cash flows provided from (used by) investing activities:
Capital expenditures	(2,882)	(1,860)
Purchase of short-term investments	(1,850)	(3,225)
Sale of short-term investments	2,325	900
Purchase of long-term investments	(63)
Proceeds on sale of assets	18	4
Other	1	3
Net cash (used by) investing activities	(2,451)	(4,178)
Cash flows provided from (used by) financing activities:
Long-term debt principal payments	(64)	(11)
Net proceeds from long-term debt borrowings	2,278	1,200
Premium paid to retire debt	(10)
Financing costs paid	(56)	(17)
Finance lease obligation payments	(18)	(15)
Proceeds from sale and lease-back transactions	21	70
Taxes paid on behalf of employees for shares withheld	(9)	(7)
Other	(7)	(1)
Net cash provided from financing activities	2,135	1,219
Increase (Decrease) in cash, cash equivalents, and restricted cash	732	(1,918)
Cash, cash equivalents, and restricted cash at January 1,	322	2,178
Cash, cash equivalents, and restricted cash at September 30,	1,054	260
Supplemental cash flow information: Cash paid during the period for:
Interest	449	286
Income tax payments, net	$ 1	$ 7