Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES
Net income	$ 2,591	$ 2,454
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,186	1,146
Deferred income taxes	240	144
Long-term casualty and environmental liabilities, net	(9)	(19)
Other, net	(239)	(93)
Changes in current assets and liabilities:
Accounts receivable, net	(39)	(14)
Materials and supplies	9	14
Other current assets	(165)	(104)
Accounts payable and other current liabilities	471	266
Net cash provided by operating activities	4,045	3,794
INVESTING ACTIVITIES
Capital expenditures excluding equipment	(1,417)	(1,224)
Acquisition of equipment	(111)	(72)
Purchases of investments and investments in time deposits	(6)	(13)
Proceeds from sales of investments and maturities of time deposits	7	17
Other, net	(73)	(108)
Net cash used for investing activities	(1,600)	(1,400)
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	0	750
Payments on long-term debt	(36)	(696)
Cash distributions	(2,400)	(2,275)
Other, net	0	(9)
Net cash used for financing activities	(2,436)	(2,230)
Increase in cash and cash equivalents	9	164
Cash and cash equivalents:
Beginning of period	1,985	1,975
End of period	1,994	2,139
SUPPLEMENTAL CASH FLOW INFORMATION
Interest paid, net of amounts capitalized	529	532
Capital investments accrued but not yet paid	163	93
Income taxes paid, net of refunds	163	226
Non-cash asset financing	$ 6	$ 0