DERIVATIVES - Offsetting of Financial Assets and Liabilities and Derivative Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Total derivatives
Assets
Gross Amount Recognized	$ 5,779	$ 5,852
Gross Amount Recognized	5,522	5,466
Net Amount Presented in the Balance Sheets	257	386
Gross Amount not Offset in the Balance Sheets	(162)	(77)
Net Amount	95	309
Liabilities
Gross Amount Recognized	7,354	5,512
Gross Amount Offset in the Balance Sheets	5,522	5,466
Net Amount Presented in the Balance Sheets	1,832	46
Gross Amount not Offset in the Balance Sheets	0	0
Net Amount	1,832	46
Other financial instruments
Assets
Gross Amount Recognized	1,855	2,394
Gross Amount Recognized	0	0
Net Amount Presented in the Balance Sheets	1,855	2,394
Gross Amount not Offset in the Balance Sheets	0	0
Net Amount	1,855	2,394
Other invested assets
Assets
Gross Amount Recognized	7,634	8,246
Gross Amount Recognized	5,522	5,466
Net Amount Presented in the Balance Sheets	2,112	2,780
Gross Amount not Offset in the Balance Sheets	(162)	(77)
Net Amount	1,950	2,703
Other financial liabilities
Liabilities
Gross Amount Recognized	3,884	3,924
Gross Amount Offset in the Balance Sheets	0	0
Net Amount Presented in the Balance Sheets	3,884	3,924
Gross Amount not Offset in the Balance Sheets	0	0
Net Amount	3,884	3,924
Other liabilities
Liabilities
Gross Amount Recognized	11,238	9,436
Gross Amount Offset in the Balance Sheets	5,522	5,466
Net Amount Presented in the Balance Sheets	5,716	3,970
Gross Amount not Offset in the Balance Sheets	0	0
Net Amount	$ 5,716	$ 3,970