Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$ 3,046us-gaap_NetIncomeLoss	$ 1,753us-gaap_NetIncomeLoss	$ 1,582us-gaap_NetIncomeLoss
Postretirement and postemployment plans
Change in actuarial loss and other	(52)	300	(97)
Income tax benefit (provision) on postretirement and postemployment plans	25	(112)	35
Postretirement and postemployment plans, net of tax	(27)	188	(62)
Derivative hedges
Net unrecognized gain	1	1	1
Income tax provision on derivative hedges	0	0	0
Derivative hedges, net of tax	1	1	1
Foreign currency translation and other
Unrealized gain (loss)	0	(3)	1
Income tax benefit (provision) on foreign currency translation and other	(1)	1	(3)
Foreign currency translation and other, net of tax	(1)	(2)	(2)
Other comprehensive income (loss)	(27)	187	(63)
Comprehensive income	$ 3,019	$ 1,940	$ 1,519

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Includes foreign currency and available-for-sale securities. For foreign currency, it is the adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into functional currency of the reporting entity, net of tax. For available-for-sale securities, it is the gross appreciation or the gross loss in value of the total unsold securities at the end of an accounting period, after tax.

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Includes foreign currency and available-for-sale securities. For foreign currency, it is the pre-tax adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains (losses). Includes gain (loss) on foreign currency forward exchange contracts. Includes foreign currency transactions designated as hedges of net investment in a foreign entity and intercompany foreign currency transactions that are of a long-term nature, when the entities to the transaction are consolidated, combined, or accounted for by the equity method in the reporting enterprise's financial statements. Includes the gain or loss on a derivative instrument or nonderivative financial instrument that may give rise to a foreign currency transaction gain or loss under FAS 52 and that have been designated and have qualified as hedging instruments for hedges of the foreign currency exposure of a net investment in a foreign operation. For available-for-sale securities, it is the gross appreciation or the gross loss in value of the total of unsold available-for-sale securities (except when designated as a fair value hedge or which had been determined to have had an other than temporary decline in fair value below its amortized cost basis) at the end of an accounting period.

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Includes foreign currency and available-for-sale securities. For foreign currency, it is the tax effect of the adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into functional currency of the reporting entity. For available-for-sale securities, it is the tax effect of the gross appreciation or the gross loss, net of reclassification adjustment, in the change in value of available for sale securities during the period.

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Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount before tax, after reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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