Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income	$ 5,481	$ 5,219	$ 11,300
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,403	2,317	2,352
Deferred income taxes	553	381	(6,435)
Long-term casualty and environmental liabilities, net	(49)	(18)	(85)
Other, net	(351)	(147)	(289)
Changes in current assets and liabilities:
Accounts receivable, net	134	(48)	(177)
Materials and supplies	4	10	22
Other current assets	(110)	(52)	(163)
Accounts payable and other current liabilities	122	246	(206)
Net cash provided by operating activities	8,187	7,908	6,319
Investing Activities
Capital expenditures excluding equipment	(3,193)	(2,918)	(2,860)
Acquisition of equipment	(415)	(269)	(397)
Purchases of investments and investments in time deposits	(6)	(27)	(13)
Proceeds from sales of investments and maturities of time deposits	42	45	34
Other, net	(170)	(11)	(247)
Net cash used for investing activities	(3,742)	(3,180)	(3,483)
Financing Activities
Proceeds from issuance of long-term debt	825	1,500	1,250
Payments on long-term debt and finance leases	(833)	(746)	(735)
Cash distributions	(4,425)	(5,450)	(4,575)
Other, net	(13)	(22)	(19)
Net cash used for financing activities	(4,446)	(4,718)	(4,079)
(Decrease) increase in cash and cash equivalents	(1)	10	(1,243)
Cash and cash equivalents:
Beginning of period	1,985	1,975	3,218
End of period	1,984	1,985	1,975
Supplemental Cash Flow Information
Interest paid, net of amounts capitalized	1,064	1,072	1,062
Capital investments accrued but not yet paid	245	251	192
Income taxes paid, net of refunds	1,196	905	1,789
Non-cash asset financing	$ 11	$ 8	$ 0