Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
OPERATING ACTIVITIES
Net income	$ 3,847	$ 2,838
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,726	1,756
Deferred income taxes	279	426
Long-term casualty and environmental liabilities, net	(24)	(63)
Other, net	(106)	(133)
Changes in current assets and liabilities:
Accounts receivable, net	(125)	(99)
Materials and supplies	(23)	18
Other current assets	(55)	11
Accounts payable and other current liabilities	424	14
Net cash provided by operating activities	5,943	4,768
INVESTING ACTIVITIES
Capital expenditures excluding equipment	(2,022)	(2,107)
Acquisition of equipment	(134)	(280)
Purchases of investments and investments in time deposits	(23)	(9)
Proceeds from sales of investments and maturities of time deposits	37	25
Other, net	(114)	(204)
Net cash used for investing activities	(2,256)	(2,575)
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	1,500	1,250
Payments on long-term debt	(711)	(710)
Cash distributions	(4,150)	(2,625)
Other, net	(21)	(20)
Net cash used for financing activities	(3,382)	(2,105)
Increase in cash and cash equivalents	305	88
Cash and cash equivalents:
Beginning of period	1,975	3,218
End of period	2,280	3,306
SUPPLEMENTAL CASH FLOW INFORMATION
Interest paid, net of amounts capitalized	819	833
Capital investments accrued but not yet paid	166	147
Income taxes paid, net of refunds	540	1,193
Non-cash asset financing	$ 4	$ 0