Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
OPERATING ACTIVITIES
Net income	$ 11,300	$ 3,569	$ 4,248
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,352	2,128	2,001
Deferred income taxes, adjusted	(6,435)
Deferred income taxes	(6,421)	998	1,148
Long-term casualty and environmental liabilities, net	(85)	(35)	(35)
Other, net	(289)	27	(47)
Changes in current assets and liabilities:
Accounts receivable, net	(177)	(74)	196
Materials and supplies	22	4	(34)
Other current assets	(163)	(129)	(4)
Accounts payable and other current liabilities	(206)	437	(298)
Net cash provided by operating activities	6,319	6,925	7,175
INVESTING ACTIVITIES
Capital expenditures excluding equipment	(2,860)	(3,205)	(4,425)
Acquisition of equipment	(397)	(614)	(1,226)
Purchases of Investments and investments in time deposits	(13)	(8)	(151)
Proceeds from sales of investments and maturities of time deposits	34	27	27
Partnership Investment	0	0	(36)
Other, net	(247)	(181)	(16)
Net cash used for investing activities	(3,483)	(3,981)	(5,827)
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	1,250	750	3,000
Payments on long-term debt	(735)	(292)	(371)
Cash distributions	(4,575)	(2,500)	(4,000)
Other, net	(19)	(13)	(32)
Net cash used for financing activities	(4,079)	(2,055)	(1,403)
Increase/(decrease) in cash and cash equivalents	(1,243)	889	(55)
Cash and cash equivalents:
Beginning of period	3,218	2,329	2,384
End of period	1,975	3,218	2,329
SUPPLEMENTAL CASH FLOW INFORMATION
Interest paid, net of amounts capitalized	1,062	1,016	953
Capital investments accrued but not yet paid	192	305	421
Income taxes paid, net of refunds	$ 1,789	$ 752	$ 1,281