FAIR VALUE DISCLOSURES - FAIR VALUE MEASUREMENT RECONCILIATION FOR ALL LEVELS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total Gains Losses Realized Unrealized Included In [Abstract]
Investment gains (losses), net	$ 206	$ 3	$ (125)
Transfers into level 3	14	83
Transfers out of Level 3	(540)	(28)
Corporate
Total Gains Losses Realized Unrealized Included In [Abstract]
Other comprehensive income (loss)	3	(18)	4
States and political subdivisions
Total Gains Losses Realized Unrealized Included In [Abstract]
Other comprehensive income (loss)	3	(1)
Commercial mortgage-backed
Total Gains Losses Realized Unrealized Included In [Abstract]
Other comprehensive income (loss)	0		45
Asset- backed
Total Gains Losses Realized Unrealized Included In [Abstract]
Other comprehensive income (loss)	0	(7)	(9)
GMIB reinsurance contracts
Total Gains Losses Realized Unrealized Included In [Abstract]
Other comprehensive income (loss)	0	0	0
GMxB derivative features liability
Total Gains Losses Realized Unrealized Included In [Abstract]
Other comprehensive income (loss)	0	0	0
Level 3 | Corporate
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	1,174	1,139	845
Net investment income (loss)	4	7	5
Investment gains (losses), net	0	(8)	2
Subtotal	4	(1)	7
Other comprehensive income (loss)	5	(20)	4
Purchases	273	322	612
Sales	(120)	(321)	(331)
Transfers into level 3	14	83	7
Transfers out of Level 3	(104)	(28)	(5)
Closing Balance	1,246	1,174	1,139
Level 3 | States and political subdivisions
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	38	40	42
Net investment income (loss)	0	0	0
Investment gains (losses), net	0	0	0
Subtotal	0	0	0
Other comprehensive income (loss)	3	(1)	(1)
Purchases	0	0	0
Sales	(2)	(1)	(1)
Transfers into level 3	0	0	0
Transfers out of Level 3	0	0	0
Closing Balance	39	38	40
Level 3 | Commercial mortgage-backed
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	0	0	349
Net investment income (loss)	0	0	(2)
Investment gains (losses), net	0	0	(63)
Subtotal	0	0	(65)
Other comprehensive income (loss)	0	0	45
Purchases	0	0	0
Sales	0	0	(329)
Transfers into level 3	0	0	0
Transfers out of Level 3	0	0	0
Closing Balance	0	0	0
Level 3 | Asset- backed
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	519	8	24
Net investment income (loss)	0	(2)	0
Investment gains (losses), net	0	0	15
Subtotal	0	(2)	15
Other comprehensive income (loss)	1	(7)	(9)
Purchases	100	550	0
Sales	(84)	(30)	(21)
Transfers into level 3	0	0	0
Transfers out of Level 3	(436)	0	(1)
Closing Balance	100	519	8
Level 3 | Redeemable preferred stock
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	0	0	1
Net investment income (loss)	0	0	0
Investment gains (losses), net	0	0	0
Subtotal	0	0	0
Other comprehensive income (loss)	0	0	(1)
Purchases	0	0	0
Sales	0	0	0
Transfers into level 3	0	0	0
Transfers out of Level 3	0	0	0
Closing Balance	0	0	0
Level 3 | Other equity investments
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	48	25	40
Investment gains (losses), net	0	0	0
Net derivative gains (losses), excluding non-performance risk	0	0	0
Nonperformance risk	0	0	0
Subtotal	0	0	0
Purchases	0	29	0
Sales	0	0	0
Settlements	0	0	0
Activity related to consolidated VIEs/VOEs	(3)	(6)	(15)
Transfers into level 3	0	5	0
Transfers out of Level 3	(29)	(5)	0
Closing Balance	16	48	25
Level 3 | GMIB reinsurance contracts
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	1,991	10,488	10,313
Investment gains (losses), net	0	0	0
Net derivative gains (losses), excluding non-performance risk	458	(972)	(6)
Nonperformance risk	42	(96)	75
Subtotal	500	(1,068)	69
Purchases	47	96	221
Sales	(72)	(62)	(115)
Settlements	0	(7,463)	0
Activity related to consolidated VIEs/VOEs	0	0	0
Transfers into level 3	0	0	0
Transfers out of Level 3	0	0	0
Closing Balance	2,466	1,991	10,488
Level 3 | Separate Accounts’ assets
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	21	22	17
Investment gains (losses), net	0	0	(1)
Net derivative gains (losses), excluding non-performance risk	0	0	0
Nonperformance risk	0	0	0
Subtotal	0	0	(1)
Purchases	0	5	12
Sales	(1)	(1)	(2)
Settlements	(2)	(5)	(4)
Activity related to consolidated VIEs/VOEs	0	0	0
Transfers into level 3	0	0	0
Transfers out of Level 3	(18)	0	0
Closing Balance	0	21	22
Level 3 | GMxB derivative features liability
Total Gains Losses Realized Unrealized Included In [Abstract]
Beginning Balance	(5,431)	(4,256)	(5,473)
Investment gains (losses), net	0	0	0
Net derivative gains (losses), excluding non-performance risk	(3,220)	(296)	1,443
Nonperformance risk	792	(490)	149
Subtotal	(2,428)	(786)	1,592
Purchases	(416)	(403)	(381)
Sales	29	14	6
Settlements	0	0	0
Activity related to consolidated VIEs/VOEs	0	0	0
Transfers into level 3	0	0	0
Transfers out of Level 3	0	0	0
Closing Balance	$ (8,246)	$ (5,431)	$ (4,256)