INVESTMENTS - Total Investments in Bank and Financial Institution Sector, Including those Classified as Perpetual Securities (Detail) - Banks/financial institutions - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 11,859	$ 12,884
Fair Value	$ 12,769	$ 14,121
Percentage of Total Investment Portfolio, Amortized Cost	12.00%	14.00%
Percentage of Total Investment Portfolio, Fair Value	12.00%	13.00%
Fixed maturities:
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 9,954	$ 10,627
Fair Value	$ 10,805	$ 11,683
Percentage of Total Investment Portfolio, Amortized Cost	10.00%	11.00%
Percentage of Total Investment Portfolio, Fair Value	10.00%	11.00%
Perpetual securities | Upper Tier II:
Summary of Investment Holdings [Line Items]
Amortized Cost	$ 1,337	$ 1,554
Fair Value	$ 1,369	$ 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	$ 568	$ 703
Fair Value	$ 595	$ 793
Percentage of Total Investment Portfolio, Amortized Cost	1.00%	1.00%
Percentage of Total Investment Portfolio, Fair Value	1.00%	1.00%