Consolidated Balance Sheets (Parenthetical)(USD ($)) In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Fixed maturities available for sale, at amortized cost	$ 47,826	$ 48,406
Fixed maturities available for sale, hybrid financial instruments	274us-gaap_HybridInstrumentsAtFairValueNet	302us-gaap_HybridInstrumentsAtFairValueNet
Fixed maturities held to maturity, at fair value	7,589	6,263
Equity securities, at cost	440	841
Other investments, cost	$ 2,999	$ 2,671
Common Shares, shares issued	342,832,412us-gaap_CommonStockSharesIssued	342,832,412us-gaap_CommonStockSharesIssued
Common Shares, shares outstanding	328,659,686us-gaap_CommonStockSharesOutstanding	339,793,935us-gaap_CommonStockSharesOutstanding
Common Shares in treasury, shares	14,172,726us-gaap_TreasuryStockShares	3,038,477us-gaap_TreasuryStockShares

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Fair value of investments in debt securities classified as held-to-maturity.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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