INVESTMENTS - Details of Holdings of Perpetual Securities (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Investment Holdings [Line Items]
Amortized Cost	$ 57,500	$ 52,275
Fair Value	60,991	54,036
Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	4,828	6,897
Fair Value	4,719	6,439
Unrealized Gain (Loss)	(109)	(458)
Perpetual Securities \| Upper Tier II
Investment Holdings [Line Items]
Amortized Cost	3,189	4,285
Fair Value	3,165	4,244
Unrealized Gain (Loss)	(24)	(41)
Perpetual Securities \| Upper Tier II \| AA
Investment Holdings [Line Items]
Amortized Cost	0	196
Fair Value	0	204
Unrealized Gain (Loss)	0	8
Perpetual Securities \| Upper Tier II \| A
Investment Holdings [Line Items]
Amortized Cost	504	2,108
Fair Value	524	2,046
Unrealized Gain (Loss)	20	(62)
Perpetual Securities \| Upper Tier II \| BBB
Investment Holdings [Line Items]
Amortized Cost	2,317	1,791
Fair Value	2,263	1,804
Unrealized Gain (Loss)	(54)	13
Perpetual Securities \| Upper Tier II \| BB or Lower
Investment Holdings [Line Items]
Amortized Cost	368	190
Fair Value	378	190
Unrealized Gain (Loss)	10	0
Perpetual Securities \| Tier I
Investment Holdings [Line Items]
Amortized Cost	1,294	2,268
Fair Value	1,183	1,834
Unrealized Gain (Loss)	(111)	(434)
Perpetual Securities \| Tier I \| A
Investment Holdings [Line Items]
Amortized Cost	60	0
Fair Value	59	0
Unrealized Gain (Loss)	(1)	0
Perpetual Securities \| Tier I \| BBB
Investment Holdings [Line Items]
Amortized Cost	1,009	1,684
Fair Value	856	1,417
Unrealized Gain (Loss)	(153)	(267)
Perpetual Securities \| Tier I \| BB or Lower
Investment Holdings [Line Items]
Amortized Cost	225	584
Fair Value	268	417
Unrealized Gain (Loss)	43	(167)
Perpetual Securities \| Other subordinated - non-banks \| BBB
Investment Holdings [Line Items]
Amortized Cost	345	344
Fair Value	371	361
Unrealized Gain (Loss)	$ 26	$ 17

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Number FAS115-1/124-1

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

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-Publisher FASB

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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-Name Statement of Financial Accounting Standard (FAS)

-Number 133

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+ Details

- Definition

This item represents the cost of debt and equity 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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