INVESTMENTS - Investments in Variable Interest Entities Not Consolidated (Details) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Securities available for sale, fixed maturities, amortized cost	[1]	$ 81,607
Securities available for sale, fixed maturities, fair value	[1]	89,033
Securities held to maturity, fixed maturities, amortized cost		33,377	$ 31,430
Securities held to maturity, fixed maturities, fair value		40,468	38,072
Other investments	[2]	5,073	3,402
Assets, fair value		95,018	89,215
Variable Interest Entity, Not Consolidated
Variable Interest Entity [Line Items]
Securities available for sale, fixed maturities, amortized cost	[3]	5,194	5,004
Securities available for sale, fixed maturities, fair value	[3]	5,749	5,724
Securities held to maturity, fixed maturities, amortized cost		2,711	2,549
Securities held to maturity, fixed maturities, fair value		3,077	2,929
Other investments		110	55
Other investments, fair value		108	55
Assets, amortized cost		8,015	7,608
Assets, fair value		$ 8,934	$ 8,708

[1] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)

[2] Includes $3,994 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities

[3] Includes perpetual securities