INSURANCE LIABILITIES - Separate Account Investments, Hedging Programs and Variable and Interest-Sensitive Live Insurance Policies (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Direct Liability
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	$ 920	$ 801	$ 893	$ 787
Paid guaranteed benefits	(13)	(3)	(26)	(10)
Other changes in reserves	35	21	75	42
Balance, end of period	942	819	942	819
Reinsurance Ceded
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	(827)	(744)	(807)	(733)
Paid guaranteed benefits	0	0	0	0
Other changes in reserves	(14)	(11)	(34)	(22)
Balance, end of period	(841)	(755)	(841)	(755)
Net
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	93	57	86	54
Paid guaranteed benefits	(13)	(3)	(26)	(10)
Other changes in reserves	21	10	41	20
Balance, end of period	101	64	101	64
GMDB
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	88,055		88,055		$ 94,488
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	(105)	(103)	(98)	(107)
Paid guaranteed benefits	(4)	(5)	(9)	(9)
Other changes in reserves	3	(2)	(9)	(2)
Balance, end of period	(98)	$ (100)	(98)	$ (100)
GMDB | Equity
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	39,126		39,126		42,489
GMDB | Fixed income
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	5,297		5,297		5,263
GMDB | Balanced
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	42,696		42,696		45,871
GMDB | Other
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	936		936		865
GMIB
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	54,792		54,792		59,348
GMIB | Equity
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	16,011		16,011		17,941
GMIB | Fixed income
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	2,682		2,682		2,699
GMIB | Balanced
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	35,835		35,835		38,445
GMIB | Other
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	$ 264		$ 264		$ 263