Schedule II - Condensed Financial Information, Balance Sheets (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Assets
Cash and cash equivalents	$ 2,620	$ 1,420	$ 2,276	$ 2,795
Other assets	2,985us-gaap_OtherAssets	2,683us-gaap_OtherAssets
Total assets	58,122us-gaap_Assets	55,896us-gaap_Assets
Liabilities:
Short-term debt	999us-gaap_DebtCurrent	147us-gaap_DebtCurrent
Long-term debt, carrying value	5,062	5,005
Total liabilities	47,081us-gaap_Liabilities	45,017us-gaap_Liabilities
Shareholders Equity:
Common stock (shares issued, 296; authorized, 600)	74us-gaap_CommonStockValue	74us-gaap_CommonStockValue
Additional paid-in capital	2,823	2,769
Accumulated other comprehensive loss	(934)	(936)
Retained earnings	10,635	10,289
Less treasury stock, at cost	(1,656)us-gaap_TreasuryStockValue	(1,422)us-gaap_TreasuryStockValue
Total shareholders' equity	10,942us-gaap_StockholdersEquity	10,774us-gaap_StockholdersEquity
Total liabilities and equity	$ 58,122	$ 55,896

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Value received from shareholders in common stock-related transactions that are in excess of par value or stated value and amounts received from other stock-related transactions. Includes only common stock transactions (excludes preferred stock transactions). May be called contributed capital, capital in excess of par, capital surplus, or paid-in capital.

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

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Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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Amount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any.

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Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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The aggregate carrying amounts, as of the balance sheet date, of assets not separately disclosed in the balance sheet.

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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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The amount allocated to treasury stock. Treasury stock is common and preferred shares of an entity that were issued, repurchased by the entity, and are held in its treasury.

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