INVESTMENTS - Investments in Variable Interest Entities Not Consolidated (Details) - USD ($) $ in Millions		Jun. 30, 2018		Dec. 31, 2017
Variable Interest Entity [Line Items]
Available for sale, fixed maturity securities, amortized cost		$ 78,935	[1],[2]	$ 75,132	[3]
Available for sale, fixed maturity securities	[4]	85,881	[1],[2]	84,313	[3]
Securities held to maturity, fixed maturities, amortized cost		31,259		31,430
Held to maturity, fixed maturity securities, fair value		37,956		38,072
Other investments	[5]	5,831		3,402
Assets, fair value disclosure		91,289		89,215
Variable Interest Entity, Not Consolidated
Variable Interest Entity [Line Items]
Available for sale, fixed maturity securities, amortized cost	[6]	4,870		5,004
Available for sale, fixed maturity securities	[6]	5,358		5,724
Securities held to maturity, fixed maturities, amortized cost		2,469		2,549
Held to maturity, fixed maturity securities, fair value		2,795		2,929
Other investments		106		55
Other investments, fair value		106		55
Assets, amortized cost		7,445		7,608
Assets, fair value disclosure		$ 8,259		$ 8,708

[1] Includes perpetual securities ($1,446 at amortized cost and $1,612 at fair value)

[2] 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)

[3] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)

[4] Includes perpetual securities

[5] Includes $4,586 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities

[6] Includes perpetual securities