Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
OPERATING ACTIVITIES
Net income	$ 2,576	$ 3,164
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,584	1,488
Deferred income taxes	906	491
Long-term casualty and environmental liabilities, net	(33)	(12)
Other, net	(98)	(36)
Changes in current assets and liabilities:
Accounts receivable, net	(75)	(7)
Materials and supplies	35	(6)
Other current assets	(288)	(76)
Accounts payable and other current liabilities	392	372
Net cash provided by operating activities	4,999	5,378
INVESTING ACTIVITIES
Capital expenditures excluding equipment	(2,392)	(3,214)
Acquisition of equipment	(493)	(877)
Purchases of investments and investments in time deposits	(5)	(149)
Proceeds from sales of investments and maturities of time deposits	24	24
Partnership investment	0	(36)
Other, net	(308)	(101)
Net cash used for investing activities	(3,174)	(4,353)
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	750	3,000
Payments on long-term debt	(266)	(337)
Cash distributions	(1,750)	(3,000)
Other, net	(13)	(32)
Net cash (used for) provided by financing activities	(1,279)	(369)
(Decrease) increase in cash and cash equivalents	546	656
Cash and cash equivalents:
Beginning of period	2,329	2,384
End of period	2,875	3,040
SUPPLEMENTAL CASH FLOW INFORMATION
Interest paid, net of amounts capitalized	804	733
Capital investments accrued but not yet paid	121	304
Income taxes paid, net of refunds	$ 297	$ 823