Schedule II - Condensed Financial Information, Balance Sheets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 1,420	$ 2,795	$ 2,978	$ 4,690
Other assets	2,683us-gaap_OtherAssets	2,654us-gaap_OtherAssets
Total assets	55,896us-gaap_Assets	54,336us-gaap_Assets
Liabilities:
Short-term debt	147us-gaap_DebtCurrent	233us-gaap_DebtCurrent
Long-term debt, carrying value	5,005	5,014
Total liabilities	45,017us-gaap_Liabilities	43,659us-gaap_Liabilities
Shareholders Equity:
Common stock (shares issued, 296, 366; authorized, 600)	74us-gaap_CommonStockValue	92us-gaap_CommonStockValue
Additional paid-in capital	2,769	3,356
Accumulated other comprehensive loss	(936)	(520)
Retained earnings	10,289	13,676
Less treasury stock, at cost	(1,422)us-gaap_TreasuryStockValue	(6,037)us-gaap_TreasuryStockValue
Total shareholders' equity	10,774us-gaap_StockholdersEquity	10,567us-gaap_StockholdersEquity
Total liabilities and equity	55,896	54,336
Parent Company [Member]
Assets
Cash and cash equivalents	51	0	115	0
Investments in subsidiaries	17,645	16,932
Intercompany	74	40
Other assets	553	435
Total assets	18,323	17,407
Liabilities:
Intercompany	1,138	1,043
Short-term debt	100	100
Long-term debt, carrying value	4,885	4,871
Other liabilities	1,426	826
Total liabilities	7,549	6,840
Shareholders Equity:
Common stock (shares issued, 296, 366; authorized, 600)	74	92
Additional paid-in capital	2,769	3,356
Accumulated other comprehensive loss	(936)	(520)
Retained earnings	10,289	13,676
Less treasury stock, at cost	(1,422)	(6,037)
Total shareholders' equity	10,774	10,567
Total liabilities and equity	$ 18,323	$ 17,407

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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.