INSURANCE LIABILITIES - Separate Account Investments, Hedging Programs and Variable and Interest-Sensitive Live Insurance Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Direct Liability
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	$ 894	$ 788	$ 678
Paid guaranteed benefits	(40)	(20)	(23)
Other changes in reserves	162	126	133
Balance, end of period	1,016	894	788
Reinsurance Ceded
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	(808)	(734)	(664)
Paid guaranteed benefits	0	0	0
Other changes in reserves	(75)	(74)	(70)
Balance, end of period	(883)	(808)	(734)
Net
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	86	54	14
Paid guaranteed benefits	(40)	(20)	(23)
Other changes in reserves	87	52	63
Balance, end of period	133	86	54
GMDB
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	100,520	94,488
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	4,775	4,657	4,056
Balance, beginning of period	(99)	(107)	(102)
Paid guaranteed benefits	(495)	(438)	(394)
Paid guaranteed benefits	(15)	(14)	(70)
Other changes in reserves	813	556	995
Other changes in reserves	0	(6)	(75)
Balance, end of period	5,093	4,775	4,657
Balance, end of period	(84)	(99)	(107)
GMDB | Equity
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	46,850	42,489
GMDB | Fixed income
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	5,506	5,263
GMDB | Balanced
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	47,053	45,871
GMDB | Other
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	1,111	865
GMIB
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	61,186	59,348
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross
Balance, beginning of period	4,671	3,744	4,765
Balance, beginning of period	(2,466)	(1,993)	(10,495)
Paid guaranteed benefits	(293)	(256)	(153)
Paid guaranteed benefits	(79)	(72)	(61)
Other changes in reserves	1,647	1,183	(868)
Other changes in reserves	(472)	(545)	8,441
Balance, end of period	6,025	4,671	3,744
Balance, end of period	(2,859)	(2,466)	$ (1,993)
GMIB | Equity
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	18,771	17,941
GMIB | Fixed income
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	2,701	2,699
GMIB | Balanced
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	39,439	38,445
GMIB | Other
Fair Value, Separate Account Investment [Line Items]
Separate Accounts	$ 275	$ 263