INVESTMENTS - DERIVATIVES GROSS COLLATERAL AMOUNTS ASSETS (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Total derivatives
Offsetting Assets [Line Items]
Fair Value of Assets	$ 1,938	$ 1,954
Collateral (Received)/Held
Financial Instruments	0	0
Cash	(1,799)	(1,828)
Net Amounts	139	126
Other financial instruments
Offsetting Assets [Line Items]
Fair Value of Assets	3,435	2,995
Collateral (Received)/Held
Financial Instruments	0	0
Cash	0	0
Net Amounts	3,435	2,995
Other invested assets
Offsetting Assets [Line Items]
Fair Value of Assets	5,373	4,949
Collateral (Received)/Held
Financial Instruments	0	0
Cash	(1,799)	(1,828)
Net Amounts	$ 3,574	$ 3,121