INVESTMENTS - Details of Holdings of Perpetual Securities (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Investment Holdings [Line Items]
Amortized Cost	$ 49,680	$ 52,275
Fair Value	51,899	54,036
Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	5,522	6,897
Fair Value	5,352	6,439
Unrealized Gain (Loss)	(170)	(458)
Perpetual Securities \| Upper Tier II
Investment Holdings [Line Items]
Amortized Cost	3,251	4,285
Fair Value	3,194	4,244
Unrealized Gain (Loss)	(57)	(41)
Perpetual Securities \| Upper Tier II \| AA
Investment Holdings [Line Items]
Amortized Cost	80	196
Fair Value	81	204
Unrealized Gain (Loss)	1	8
Perpetual Securities \| Upper Tier II \| A
Investment Holdings [Line Items]
Amortized Cost	530	2,108
Fair Value	544	2,046
Unrealized Gain (Loss)	14	(62)
Perpetual Securities \| Upper Tier II \| BBB
Investment Holdings [Line Items]
Amortized Cost	2,641	1,791
Fair Value	2,569	1,804
Unrealized Gain (Loss)	(72)	13
Perpetual Securities \| Upper Tier II \| BB or Lower
Investment Holdings [Line Items]
Amortized Cost	0	190
Fair Value	0	190
Unrealized Gain (Loss)	0	0
Perpetual Securities \| Tier I
Investment Holdings [Line Items]
Amortized Cost	1,945	2,268
Fair Value	1,807	1,834
Unrealized Gain (Loss)	(138)	(434)
Perpetual Securities \| Tier I \| A
Investment Holdings [Line Items]
Amortized Cost	60	0
Fair Value	60	0
Unrealized Gain (Loss)	0	0
Perpetual Securities \| Tier I \| BBB
Investment Holdings [Line Items]
Amortized Cost	1,350	1,684
Fair Value	1,238	1,417
Unrealized Gain (Loss)	(112)	(267)
Perpetual Securities \| Tier I \| BB or Lower
Investment Holdings [Line Items]
Amortized Cost	535	584
Fair Value	509	417
Unrealized Gain (Loss)	(26)	(167)
Perpetual Securities \| Other subordinated - non-banks \| BBB
Investment Holdings [Line Items]
Amortized Cost	326	344
Fair Value	351	361
Unrealized Gain (Loss)	$ 25	$ 17

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15E

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 22

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6379932&loc=d3e22054-111558

+ 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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