Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
OPERATING ACTIVITIES
Net income	$ 3,164	$ 2,675
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,488	1,569
Deferred income taxes	491	262
Long-term casualty and environmental liabilities, net	(12)	(20)
Other, net	(36)	(294)
Changes in current assets and liabilities:
Accounts receivable, net	(7)	(73)
Materials and supplies	(6)	(11)
Other current assets	(76)	(83)
Accounts payable and other current liabilities	372	207
Net cash provided by operating activities	5,378	4,232
INVESTING ACTIVITIES
Capital expenditures excluding equipment	(3,214)	(2,612)
Acquisition of equipment	(877)	(1,043)
Purchases of investments	(149)	0
Proceeds from sales of investments	24	0
Partnership investment	(36)	0
Other, net	(101)	60
Net cash used for investing activities	(4,353)	(3,595)
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	3,000	3,000
Payments on long-term debt	(337)	(611)
Cash distributions	(3,000)	(2,750)
Other, net	(32)	(31)
Net cash used for financing activities	(369)	(392)
Increase in cash and cash equivalents	656	245
Cash and cash equivalents:
Beginning of period	2,384	2,225
End of period	3,040	2,470
SUPPLEMENTAL CASH FLOW INFORMATION
Interest paid, net of amounts capitalized	733	675
Capital investments accrued but not yet paid	304	329
Income taxes paid, net of refunds	$ 823	$ 1,301