Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Operating Activities
Net income	$ 1,214	$ 1,143
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	675	661
Deferred income taxes	12	45
Other, net	(153)	(64)
Changes in current assets and liabilities:
Accounts receivable, net	(44)	95
Materials and supplies	31	20
Other current assets	113	(26)
Accounts payable and other current liabilities	99	(183)
Net cash provided by operating activities	1,947	1,691
Investing Activities
Capital expenditures excluding equipment	(621)	(647)
Acquisition of equipment	(31)	(75)
Purchases of investments and investments in time deposits	0	(23)
Other, net	(66)	(104)
Net cash used in investing activities	(718)	(849)
Financing Activities
Payments on long-term debt and finance leases	(2)	(6)
Cash distributions	(700)	(500)
Net cash used in financing activities	(702)	(506)
Increase (decrease) in cash and cash equivalents	527	336
Cash and cash equivalents:
Beginning of period	2,004	2,148
End of period	2,531	2,484
Supplemental Cash Flow Information
Interest paid, net of amounts capitalized	311	269
Capital investments accrued but not yet paid	131	149
Income taxes paid, net of refunds	$ 2	$ 2