INVESTMENTS - Components of Net Investment Income (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									$ 3,385	$ 3,230	$ 3,399
Less investment expenses									107	95	80
Net investment income	$ 813	$ 842	$ 822	$ 801	$ 792	$ 784	$ 777	$ 782	3,278	3,135	3,319
Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									3,214	3,094	3,249
Perpetual securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									94	114	141
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									35	3	1
Other Investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									31	15	6
Short term investments and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income									$ 11	$ 4	$ 2