Condensed Consolidated Statements of Financial Position (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,587	$ 1,586
Accounts receivable, net (Note 11)	1,564us-gaap_AccountsReceivableNetCurrent	1,611us-gaap_AccountsReceivableNetCurrent
Materials and supplies	744us-gaap_MaterialsSuppliesAndOther	712us-gaap_MaterialsSuppliesAndOther
Current deferred income taxes	250us-gaap_DeferredTaxAssetsNetCurrent	277us-gaap_DeferredTaxAssetsNetCurrent
Other current assets	334us-gaap_OtherAssetsCurrent	493us-gaap_OtherAssetsCurrent
Total current assets	4,479us-gaap_AssetsCurrent	4,679us-gaap_AssetsCurrent
Investments	1,375	1,390
Net properties (Note 12)	46,928us-gaap_PropertyPlantAndEquipmentNet	46,272us-gaap_PropertyPlantAndEquipmentNet
Other assets	363us-gaap_OtherAssetsNoncurrent	375us-gaap_OtherAssetsNoncurrent
Total assets	53,145us-gaap_Assets	52,716us-gaap_Assets
Current liabilities:
Accounts payable and other current liabilities (Note 13)	2,974	3,303
Debt due within one year (Note 15)	416	462
Total current liabilities	3,390us-gaap_LiabilitiesCurrent	3,765us-gaap_LiabilitiesCurrent
Debt due after one year (Note 15)	11,884	11,018
Deferred income taxes	14,774	14,680
Other long-term liabilities	2,040us-gaap_OtherLiabilitiesNoncurrent	2,064us-gaap_OtherLiabilitiesNoncurrent
Commitments and contingencies (Note 17)
Total liabilities	32,088us-gaap_Liabilities	31,527us-gaap_Liabilities
Common shareholders' equity:
Common shares, $2.50 par value, 1,400,000,000 authorized; 1,110,476,743 and 1,110,100,423 issued; 877,373,800 and 883,366,476 outstanding, respectively	2,776us-gaap_CommonStockValue	2,775us-gaap_CommonStockValue
Paid-in-surplus	4,351us-gaap_AdditionalPaidInCapital	4,321us-gaap_AdditionalPaidInCapital
Retained earnings	28,034	27,367
Treasury stock	(12,886)us-gaap_TreasuryStockValue	(12,064)us-gaap_TreasuryStockValue
Accumulated other comprehensive loss (Note 10)	(1,218)	(1,210)
Total common shareholders' equity	21,057us-gaap_StockholdersEquity	21,189us-gaap_StockholdersEquity
Total liabilities and common shareholders' equity	$ 53,145	$ 52,716

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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