FAIR VALUE MEASUREMENTS - Additional Information (Detail) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Fair Value, Measurement Inputs, Disclosure [Line Items]
Securities held to maturity, fixed maturities, fair value	$ 48,444,000,000	$ 46,383,000,000
Interest Rates
Fair Value, Measurement Inputs, Disclosure [Line Items]
Magnitude of movement	0.50%
Credit Spreads
Fair Value, Measurement Inputs, Disclosure [Line Items]
Magnitude of movement	0.50%
Interest Rate Volatility
Fair Value, Measurement Inputs, Disclosure [Line Items]
Magnitude of movement	50.00%
Fair Value Based on Discounted Cash Flow Pricing Model
Fair Value, Measurement Inputs, Disclosure [Line Items]
Fair values of available-for-sale fixed maturity and perpetual securities valued by our DCF pricing model	18,200,000,000
Securities held to maturity, fixed maturities, fair value	$ 23,900,000,000
Available-for-sale Securities \| Level 2
Fair Value, Measurement Inputs, Disclosure [Line Items]
Percentage of fair value of investments valued by obtaining quoted market prices from investment custodian	51.00%
Percentage of holdings valued by obtaining quoted market prices from investment custodian	77.00%
Percentage of fair value of investments using DCF pricing model	42.00%
Percentage of holdings of investments using discounted cash flow pricing model	10.00%
Percentage of fair value of investments using other pricing services	7.00%
Percentage of holdings of investments using other pricing services	13.00%
Held-to-maturity Securities \| Level 2
Fair Value, Measurement Inputs, Disclosure [Line Items]
Percentage of fair value of investments valued by obtaining quoted market prices from investment custodian	3.00%
Percentage of holdings valued by obtaining quoted market prices from investment custodian	7.00%
Percentage of fair value of investments using DCF pricing model	95.00%
Percentage of holdings of investments using discounted cash flow pricing model	85.00%
Percentage of fair value of investments using other pricing services	2.00%
Percentage of holdings of investments using other pricing services	8.00%

Available for sale Fixed Maturity and Perpetual Securities, Fair Value

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- Definition

Discounted Cash Flow Pricing Model, Assumptions, Magnitude of Movement

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- Definition

Percentage of fair value of investments using Discounted Cash Flow pricing model

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Percentage of Fair Value of Investments Using Other Pricing Services

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Percentage of fair value of investments valued by obtaining quoted market prices from investment custodian

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- Definition

Percentage of Holdings of Investments Using Discounted Cash Flow Pricing Model

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Percentage of Holdings of Investments Using Other Pricing Services

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Percentage of Holdings Valued by Obtaining Quoted Market Prices from Investment Custodian

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- Definition

This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 19

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 137

-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 Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27232-111563

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