Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
Net income	$ 4,057	$ 3,847
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,788	1,726
Deferred income taxes	423	279
Long-term casualty and environmental liabilities, net	(35)	(24)
Other, net	(314)	(106)
Changes in current assets and liabilities:
Accounts receivable, net	(80)	(125)
Materials and supplies	34	(23)
Other current assets	(147)	(55)
Accounts payable and other current liabilities	71	424
Net cash provided by operating activities	5,797	5,943
INVESTING ACTIVITIES
Capital expenditures excluding equipment	(2,363)	(2,022)
Acquisition of equipment	(181)	(134)
Purchases of investments and investments in time deposits	(6)	(23)
Proceeds from sales of investments and maturities of time deposits	19	37
Other, net	(37)	(114)
Net cash used in investing activities	(2,568)	(2,256)
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	825	1,500
Payments on long-term debt	(54)	(711)
Cash distributions	(3,400)	(4,150)
Other, net	(13)	(21)
Net cash used in financing activities	(2,642)	(3,382)
Increase in cash and cash equivalents	587	305
Cash and cash equivalents:
Beginning of period	1,985	1,975
End of period	2,572	2,280
SUPPLEMENTAL CASH FLOW INFORMATION
Interest paid, net of amounts capitalized	815	819
Capital investments accrued but not yet paid	227	166
Income taxes paid, net of refunds	959	540
Non-cash asset financing	$ 8	$ 4