INVESTMENTS - Total Investments in Bank and Financial Institution Sector, Including those Classified as Perpetual Securities (Detail) - Banks/financial institutions - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 12,037	$ 12,884
Fair Value	$ 12,950	$ 14,121
Percentage of Total Investment Portfolio, Amortized Cost	13.00%	14.00%
Percentage of Total Investment Portfolio, Fair Value	13.00%	13.00%
Fixed maturities:
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 10,124	$ 10,627
Fair Value	$ 10,939	$ 11,683
Percentage of Total Investment Portfolio, Amortized Cost	11.00%	11.00%
Percentage of Total Investment Portfolio, Fair Value	11.00%	11.00%
Perpetual securities | Upper Tier II:
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 1,351	$ 1,554
Fair Value	$ 1,421	$ 1,645
Percentage of Total Investment Portfolio, Amortized Cost	1.00%	2.00%
Percentage of Total Investment Portfolio, Fair Value	1.00%	1.00%
Perpetual securities | Tier I:
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 562	$ 703
Fair Value	$ 590	$ 793
Percentage of Total Investment Portfolio, Amortized Cost	1.00%	1.00%
Percentage of Total Investment Portfolio, Fair Value	1.00%	1.00%