INVESTMENTS - Investments in Variable Interest Entities Not Consolidated (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Available for sale, fixed maturity securities, amortized cost		$ 78,706	$ 76,856
Available for sale, fixed maturity securities		87,924	82,895
Securities held to maturity, fixed maturities, amortized cost		30,163	30,318
Held to maturity, fixed maturity securities, fair value		37,446	36,722
Other investments		1,238	787
Assets, fair value		93,801	88,788
Variable Interest Entity, Not Consolidated
Variable Interest Entity [Line Items]
Available for sale, fixed maturity securities, amortized cost		4,455	4,575
Available for sale, fixed maturity securities		5,025	4,982
Securities held to maturity, fixed maturities, amortized cost		2,006	2,007
Held to maturity, fixed maturity securities, fair value		2,331	2,254
Other investments	[1]	59	49
Other investments, fair value	[1]	59	49
Assets, amortized cost		6,520	6,631
Assets, fair value		$ 7,415	$ 7,285

[1] Consists entirely of alternative investments in limited partnerships