Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES
Net income	$ 3,569	$ 4,248	$ 3,869
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	2,128	2,001	2,123
Deferred income taxes	998	1,148	941
Long-term casualty and environmental liabilities, net	(35)	(35)	(43)
Other, net	27	(47)	(310)
Changes in current assets and liabilities:
Accounts receivable, net	(74)	196	(88)
Materials and supplies	4	(34)	40
Other current assets	(129)	(4)	(36)
Accounts payable and other current liabilities	437	(298)	85
Net cash provided by operating activities	6,925	7,175	6,581
INVESTING ACTIVITIES
Capital expenditures excluding equipment	(3,205)	(4,425)	(3,734)
Acquisition of equipment	(614)	(1,226)	(1,509)
Purchases of Investments and investments in time deposits	(8)	(151)	0
Proceeds from sales of investments and maturities of time deposits	27	27	0
Partnership Investment	0	(36)	0
Other, net	(181)	(16)	(6)
Net cash used for investing activities	(3,981)	(5,827)	(5,249)
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	750	3,000	3,000
Payments on long-term debt	(292)	(371)	(641)
Cash distributions	(2,500)	(4,000)	(3,500)
Other, net	(13)	(32)	(32)
Net cash used for financing activities	(2,055)	(1,403)	(1,173)
Increase/(decrease) in cash and cash equivalents	889	(55)	159
Cash and cash equivalents:
Beginning of period	2,329	2,384	2,225
End of period	3,218	2,329	2,384
SUPPLEMENTAL CASH FLOW INFORMATION
Interest paid, net of amounts capitalized	1,016	953	859
Capital investments accrued but not yet paid	305	421	293
Income taxes paid, net of refunds	$ 752	$ 1,281	$ 1,366