INVESTMENTS - Pretax Other-Than-Temporary Impairment Losses by Investment Category (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	$ 203	[1]	$ 405	[2]
Perpetual Securities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	140		0
Corporate Bonds
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	63		397
Mortgage- and asset-backed Securities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	0		6
Municipalities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	0		1
Equity Securities
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	0		1
Credit Related Impairment [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	28
Change In Intent Impairment [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment losses	$ 175

[1] Includes $28 for credit-related impairments and $175 from change in intent to sell securities

[2] Consisted completely of credit-related impairments