Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]

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- Definition

Alternative investments - Distressed consists of investments in private equity funds targeting distressed debt/credit and equity opportunities in the US.

+ Details

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- Definition

Alternative investments - Financial primarily consists of investments in private equity funds targeting financial services companies.

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- Definition

Alternative investments - Investment funds employ various investment strategies such as long/short equity and arbitrage/distressed.

+ Details

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- Definition

Alternative investments - Mezzanine consists of investments in private equity funds targeting private mezzanine debt of large cap and mid cap companies in the US and worldwide.

+ Details

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- Definition

Alternative investments - Real Estate consists of investments in private equity funds targeting global distress opportunities, value added US properties, and global mezzanine debt securities in the commercial real estate market.

+ Details

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- Definition

Total of alternative investments.

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- Definition

Alternative investments - Traditional consists of investments in private equity funds employing traditional private equity investment strategies such as buyout and venture with different geographical focuses including Brazil, India, Asia, Europe, and the US.

+ Details

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- Definition

Alternative investments - Vintage consists of investments in private equity funds made before 2002 and where the funds' commitment periods had already expired.

+ Details

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- Definition

Liquidation period in years for distressed alternative investments (consists of investments in private equity funds targeting distressed debt/credit and equity opportunities in the US.)

+ Details

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- Definition

Liquidation period in years for financial alternative investments (primarily consists of investments in private equity funds targeting financial services companies).

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- Definition

Liquidation period in years for mezzanine alternative investments (consists of investments in private equity funds targeting private mezzanine debt of large cap and mid cap companies in the US and worldwide).

+ Details

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- Definition

Liquidation period in years for real estate alternative investments (consists of investments in private equity funds targeting global distress opportunities, value added US properties, and global mezzanine debt securities in the commercial real estate market).

+ Details

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- Definition

Liquidation period in years for traditional alternative investments (consists of investments in private equity funds employing traditional private equity investment strategies such as buyout and venture with different geographical focuses including Brazil, India, Asia, Europe, and the US.)

+ Details

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Liquidation period in years for vintage alternative investments (consists of investments in private equity funds made before 2002 and where the funds' commitment periods had already expired.)

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Notice period in days for redemption of investment funds alternative investments (employ various investment strategies such as long/short equity and arbitrage/distressed.)

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Fair Value Measurements (Fair Value And Maximum Future Funding Commitments Relating To Included In Other Investments) (Details) (USD $) In Millions, unless otherwise specified					9 Months Ended
	Sep. 30, 2011 Fair Value [Member]	Dec. 31, 2010 Fair Value [Member]	Sep. 30, 2011 Maximum Future Funding Commitments [Member]	Dec. 31, 2010 Maximum Future Funding Commitments [Member]	Sep. 30, 2011 Liquidation Period Lower Range [Member]	Sep. 30, 2011 Liquidation Period Upper Range [Member]	Sep. 30, 2011 Redemption Notice Periods Lower Range [Member]	Sep. 30, 2011 Redemption Notice Periods Upper Range [Member]
Fair Value And Maximum Future Funding Commitments Related To Investments [Line Items]
Financial	$ 204	$ 192	$ 146	$ 151
Real estate	234	168	105	92
Distressed	189	243	40	43
Mezzanine	162	135	318	173
Traditional	507	376	258	291
Vintage	23	27	2	3
Investment funds	388	329
Alternative investments total	$ 1,707	$ 1,470	$ 869	$ 753
Liquidation period for financial alternative investments (in years)					5	9
Liquidation period for real estate alternative investments (in years)					3	9
Liquidation period for distressed alternative investments (in years)					6	9
Liquidation period for mezzanine alternative investments (in years)					6	9
Liquidation period for traditional alternative investments (in years)					3	8
Liquidation period for vintage alternative investments (in years)					1	3
Notice periods for redemption of investment funds alternative investments (in days)							5	120