INVESTMENTS - Investments in Variable Interest Entities Not Consolidated (Details) - USD ($) $ in Millions		Jun. 30, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Available for sale, fixed maturity securities, amortized cost		$ 81,195	$ 76,856
Available for sale, fixed maturity securities		92,435	82,895
Securities held to maturity, fixed maturities, amortized cost		31,007	30,318
Held to maturity, fixed maturity securities, fair value		39,035	36,722
Other investments		1,427	787
Assets, fair value		97,744	88,788
Variable Interest Entity, Not Consolidated
Variable Interest Entity [Line Items]
Available for sale, fixed maturity securities, amortized cost		4,309	4,575
Available for sale, fixed maturity securities		4,961	4,982
Securities held to maturity, fixed maturities, amortized cost		2,019	2,007
Held to maturity, fixed maturity securities, fair value		2,389	2,254
Other investments	[1]	61	49
Other investments, fair value	[1]	61	49
Assets, amortized cost		6,389	6,631
Assets, fair value		$ 7,411	$ 7,285

[1] Consists entirely of alternative investments in limited partnerships