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SCHEDULE IV REINSURANCE Schedule IV - Reinsurance (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount	$ 144,374us-gaap_LifeInsuranceInForceGross				$ 157,022us-gaap_LifeInsuranceInForceGross				$ 144,374us-gaap_LifeInsuranceInForceGross	$ 157,022us-gaap_LifeInsuranceInForceGross	$ 173,791us-gaap_LifeInsuranceInForceGross
Ceded to Other Companies	3,298us-gaap_LifeInsuranceInForceCeded				3,245us-gaap_LifeInsuranceInForceCeded				3,298us-gaap_LifeInsuranceInForceCeded	3,245us-gaap_LifeInsuranceInForceCeded	3,867us-gaap_LifeInsuranceInForceCeded
Assumed from Other Companies	0us-gaap_LifeInsuranceInForceAssumed				0us-gaap_LifeInsuranceInForceAssumed				0us-gaap_LifeInsuranceInForceAssumed	0us-gaap_LifeInsuranceInForceAssumed	0us-gaap_LifeInsuranceInForceAssumed
Net Amount	141,076us-gaap_LifeInsuranceInForceNet				153,777us-gaap_LifeInsuranceInForceNet				141,076us-gaap_LifeInsuranceInForceNet	153,777us-gaap_LifeInsuranceInForceNet	169,924us-gaap_LifeInsuranceInForceNet
Percentage of Amount Assumed to Net	0.00%				0.00%				0.00%	0.00%	0.00%
Gross amount									19,412us-gaap_DirectPremiumsEarned	20,233us-gaap_DirectPremiumsEarned	22,167us-gaap_DirectPremiumsEarned
Ceded to Other Companies									350us-gaap_CededPremiumsEarned	110us-gaap_CededPremiumsEarned	33us-gaap_CededPremiumsEarned
Assumed from Other companies									10us-gaap_AssumedPremiumsEarned	12us-gaap_AssumedPremiumsEarned	14us-gaap_AssumedPremiumsEarned
Net Amount	4,489us-gaap_PremiumsEarnedNet	4,841us-gaap_PremiumsEarnedNet	4,888us-gaap_PremiumsEarnedNet	4,854us-gaap_PremiumsEarnedNet	4,910us-gaap_PremiumsEarnedNet	5,028us-gaap_PremiumsEarnedNet	5,013us-gaap_PremiumsEarnedNet	5,184us-gaap_PremiumsEarnedNet	19,072us-gaap_PremiumsEarnedNet	20,135us-gaap_PremiumsEarnedNet	22,148us-gaap_PremiumsEarnedNet
Percentage of Amount Assumed to Net									0.00%us-gaap_PremiumsPercentageAssumedToNet	0.00%us-gaap_PremiumsPercentageAssumedToNet	0.00%us-gaap_PremiumsPercentageAssumedToNet
Health insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									14,648	15,393	17,541
Ceded to Other Companies									339	98	19
Assumed from Other companies									10	12	14
Net Amount									14,319	15,307	17,536
Percentage of Amount Assumed to Net									0.00%	0.00%	0.00%
Life insurance
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross amount									4,764	4,840	4,626
Ceded to Other Companies									11	12	14
Assumed from Other companies									0	0	0
Net Amount									$ 4,753	$ 4,828	$ 4,612
Percentage of Amount Assumed to Net									0.00%	0.00%	0.00%