INVESTMENTS - Total Investments in Bank and Financial Institution Sector, Including those Classified as Perpetual Securities (Detail) (Banks/financial Institutions, USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 16,872	$ 20,196
Fair Value	15,957	20,575
Percentage of Total Investment Portfolio, Amortized Cost	17.00%	18.00%
Percentage of Total Investment Portfolio, Fair Value	16.00%	18.00%
Fixed Maturities
Summary of Investment Holdings [Line Items]
Amortized Cost	13,878	16,292
Fair Value	13,326	16,625
Percentage of Total Investment Portfolio, Amortized Cost	14.00%	14.00%
Percentage of Total Investment Portfolio, Fair Value	13.00%	14.00%
Perpetual Securities | Upper Tier II
Summary of Investment Holdings [Line Items]
Amortized Cost	2,084	2,825
Fair Value	1,877	2,919
Percentage of Total Investment Portfolio, Amortized Cost	2.00%	3.00%
Percentage of Total Investment Portfolio, Fair Value	2.00%	3.00%
Perpetual Securities | Tier I
Summary of Investment Holdings [Line Items]
Amortized Cost	910	1,079
Fair Value	$ 754	$ 1,031
Percentage of Total Investment Portfolio, Amortized Cost	1.00%	1.00%
Percentage of Total Investment Portfolio, Fair Value	1.00%	1.00%