Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net income	$ 1,371	$ 1,251
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	627	619
Deferred income taxes	(122)	58
Long-term casualty and environmental liabilities, net	(1)	7
Other, net	(75)	(69)
Changes in current assets and liabilities:
Accounts receivable, net	(83)	(48)
Materials and supplies	(116)	(49)
Other current assets	(14)	(32)
Accounts payable and other current liabilities	472	219
Net cash provided by operating activities	2,059	1,956
Investing Activities
Capital expenditures excluding equipment	(598)	(530)
Acquisition of equipment	(18)	(26)
Proceeds from sales of investments and maturities of time deposits	0	1
Other, net	(70)	(29)
Net cash used in investing activities	(686)	(584)
Financing Activities
Payments on long-term debt and finance leases	(202)	(407)
Cash distributions	(1,000)	(1,000)
Net cash used in financing activities	(1,202)	(1,407)
Increase (decrease) in cash and cash equivalents	171	(35)
Cash and cash equivalents:
Beginning of period	1,758	1,986
End of period	1,929	1,951
Supplemental Cash Flow Information
Interest paid, net of amounts capitalized	290	300
Capital investments accrued but not yet paid	141	129
Income taxes paid, net of refunds	5	7
Non-cash asset financing	$ 1	$ 4