FAIR VALUE OF ASSETS AND LIABILITIES - Quantitative Information Regarding Internally-Prices Level 3 Assets and Liabilities (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Assets
Debt securities, available-for-sale	$ 4,839	$ 5,024
Deposit asset	430	607
Net modified coinsurance receivable	0	18
Liabilities:
Insurance liabilities, at fair value	4,574	5,546
Net modified coinsurance payable	68	0
Retained Business
Assets
Net modified coinsurance receivable		0
Liabilities:
Insurance liabilities, at fair value	2,542	2,941
Net modified coinsurance payable	0
Ceded Business
Assets
Net modified coinsurance receivable		18
Liabilities:
Insurance liabilities, at fair value	2,032	$ 2,605
Net modified coinsurance payable	$ 68
Level 3 | Minimum
Liabilities:
Policyholder age	45 years
Level 3 | Minimum | Mortality rate
Liabilities:
Insurance liability, measurement input	0
Level 3 | Maximum
Liabilities:
Policyholder age	90 years
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Equality volatility curve | Retained Business
Liabilities:
Insurance liability, measurement input	0.17	0.195
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Equality volatility curve | Ceded Business
Liabilities:
Insurance liability, measurement input	0.17	0.195
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Lapse rate | Retained Business
Liabilities:
Insurance liability, measurement input	0.0065	0.01
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Lapse rate | Ceded Business
Liabilities:
Insurance liability, measurement input	0.0065	0.01
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Spread over risk free | Retained Business
Liabilities:
Insurance liability, measurement input	0.0000	0.0000
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Spread over risk free | Ceded Business
Liabilities:
Insurance liability, measurement input	0.0000	0.0000
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Utilization rate | Retained Business
Liabilities:
Insurance liability, measurement input	0.875	0.925
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Utilization rate | Ceded Business
Liabilities:
Insurance liability, measurement input	0.875	0.925
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Mortality rate | Retained Business
Liabilities:
Insurance liability, measurement input	0	0
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Mortality rate | Ceded Business
Liabilities:
Insurance liability, measurement input	0	0
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Corporate Securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0501	0.0475
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Foreign corporate private securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0469
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Foreign corporate private securities | Discount rate | Ceded Business
Assets
Debt securities, measurement input	0.1358
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Foreign corporate public securities | Discount rate | Retained Business
Assets
Debt securities, measurement input		0.0433
Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Asset-backed securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0765	0.0719
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Equality volatility curve | Retained Business
Liabilities:
Insurance liability, measurement input	0.25	0.26
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Equality volatility curve | Ceded Business
Liabilities:
Insurance liability, measurement input	0.25	0.26
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Lapse rate | Retained Business
Liabilities:
Insurance liability, measurement input	0.13	0.20
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Lapse rate | Ceded Business
Liabilities:
Insurance liability, measurement input	0.13	0.20
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Spread over risk free | Retained Business
Liabilities:
Insurance liability, measurement input	0.0225	0.0243
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Spread over risk free | Ceded Business
Liabilities:
Insurance liability, measurement input	0.0195	0.0221
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Utilization rate | Retained Business
Liabilities:
Insurance liability, measurement input	1	1
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Utilization rate | Ceded Business
Liabilities:
Insurance liability, measurement input	1	1
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Mortality rate | Retained Business
Liabilities:
Insurance liability, measurement input	0.16	0.16
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Mortality rate | Ceded Business
Liabilities:
Insurance liability, measurement input	0.16	0.16
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Corporate Securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0924	0.0803
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Foreign corporate private securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0689
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Foreign corporate private securities | Discount rate | Ceded Business
Assets
Debt securities, measurement input	0.2000
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Foreign corporate public securities | Discount rate | Retained Business
Assets
Debt securities, measurement input		0.0638
Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Asset-backed securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0899	0.0851
Level 3 | Valuation Technique, Discounted Cash Flow | Weighted Average | Corporate Securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0722	0.0656
Level 3 | Valuation Technique, Discounted Cash Flow | Weighted Average | Foreign corporate private securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0579
Level 3 | Valuation Technique, Discounted Cash Flow | Weighted Average | Foreign corporate private securities | Discount rate | Ceded Business
Assets
Debt securities, measurement input	0.1445
Level 3 | Valuation Technique, Discounted Cash Flow | Weighted Average | Foreign corporate public securities | Discount rate | Retained Business
Assets
Debt securities, measurement input		0.0536
Level 3 | Valuation Technique, Discounted Cash Flow | Weighted Average | Asset-backed securities | Discount rate | Retained Business
Assets
Debt securities, measurement input	0.0844	0.0794
Level 3 | Valuation Technique, Level Yield | Minimum | Residential mortgage loans | Market yield | Retained Business
Assets
Loans receivable, measurement input	0.0643	0.0575
Level 3 | Valuation Technique, Level Yield | Maximum  | Residential mortgage loans | Market yield | Retained Business
Assets
Loans receivable, measurement input	0.1026	0.0997
Level 3 | Valuation Technique, Level Yield | Weighted Average | Residential mortgage loans | Market yield | Retained Business
Assets
Loans receivable, measurement input	0.0819	0.0840
Recurring
Assets
Debt securities, available-for-sale	$ 4,832	$ 5,024
Mortgage and other loans	422	196
Deposit asset	430	607
Liabilities:
Insurance liabilities, at fair value	4,574	5,546
Net modified coinsurance payable	68
Recurring | Retained Business
Assets
Debt securities, available-for-sale	3,708	3,616
Mortgage and other loans	422	196
Liabilities:
Insurance liabilities, at fair value	2,542	2,941
Recurring | Ceded Business
Assets
Debt securities, available-for-sale	1,124	1,408
Deposit asset	430	607
Liabilities:
Insurance liabilities, at fair value	2,032	2,605
Recurring | Foreign corporate private securities
Assets
Debt securities, available-for-sale	78	67
Recurring | Foreign corporate private securities | Retained Business
Assets
Debt securities, available-for-sale	43	36
Recurring | Foreign corporate private securities | Ceded Business
Assets
Debt securities, available-for-sale	35	31
Recurring | Foreign corporate public securities
Assets
Debt securities, available-for-sale	143	211
Recurring | Foreign corporate public securities | Retained Business
Assets
Debt securities, available-for-sale	114	122
Recurring | Foreign corporate public securities | Ceded Business
Assets
Debt securities, available-for-sale	29	89
Recurring | Asset-backed securities
Assets
Debt securities, available-for-sale	919	532
Recurring | Asset-backed securities | Retained Business
Assets
Debt securities, available-for-sale	919	513
Recurring | Asset-backed securities | Ceded Business
Assets
Debt securities, available-for-sale		19
Recurring | Commercial mortgage-backed securities
Assets
Debt securities, available-for-sale	16	43
Recurring | Commercial mortgage-backed securities | Retained Business
Assets
Debt securities, available-for-sale	16	43
Recurring | Level 3
Assets
Debt securities, available-for-sale	466	337
Mortgage and other loans	422	196
Deposit asset	430	607
Liabilities:
Insurance liabilities, at fair value	4,574	5,546
Net modified coinsurance payable	68
Recurring | Level 3 | Retained Business
Assets
Debt securities, available-for-sale	461	337
Mortgage and other loans	422	196
Liabilities:
Insurance liabilities, at fair value	2,542	2,941
Recurring | Level 3 | Ceded Business
Assets
Debt securities, available-for-sale	5	0
Deposit asset	430	607
Net modified coinsurance receivable		18
Liabilities:
Insurance liabilities, at fair value	2,032	2,605
Recurring | Level 3 | Corporate Securities | Retained Business
Assets
Debt securities, available-for-sale	205
Recurring | Level 3 | Foreign corporate private securities
Assets
Debt securities, available-for-sale	48	36
Recurring | Level 3 | Foreign corporate private securities | Retained Business
Assets
Debt securities, available-for-sale	43	36
Recurring | Level 3 | Foreign corporate private securities | Ceded Business
Assets
Debt securities, available-for-sale	5	0
Recurring | Level 3 | Foreign corporate public securities
Assets
Debt securities, available-for-sale	0	0
Recurring | Level 3 | Foreign corporate public securities | Retained Business
Assets
Debt securities, available-for-sale	0	0
Recurring | Level 3 | Foreign corporate public securities | Ceded Business
Assets
Debt securities, available-for-sale	0	0
Recurring | Level 3 | Asset-backed securities
Assets
Debt securities, available-for-sale	213	155
Recurring | Level 3 | Asset-backed securities | Retained Business
Assets
Debt securities, available-for-sale	213	155
Recurring | Level 3 | Asset-backed securities | Ceded Business
Assets
Debt securities, available-for-sale		0
Recurring | Level 3 | Commercial mortgage-backed securities
Assets
Debt securities, available-for-sale	0	0
Recurring | Level 3 | Commercial mortgage-backed securities | Retained Business
Assets
Debt securities, available-for-sale	0	0
Recurring | Level 3 | Reinsurance recoverables | Ceded Business
Assets
Reinsurance recoverables	179	235
Recurring | Level 3 | Policyholders' account balances
Liabilities:
Net modified coinsurance payable	68
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Retained Business
Liabilities:
Insurance liabilities, at fair value	2,542	2,941
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Ceded Business
Liabilities:
Insurance liabilities, at fair value	2,032	2,605
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Corporate Securities | Retained Business
Assets
Debt securities, available-for-sale	173	146
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Foreign corporate private securities | Retained Business
Assets
Debt securities, available-for-sale	34
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Foreign corporate private securities | Ceded Business
Assets
Debt securities, available-for-sale	5
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Foreign corporate public securities | Retained Business
Assets
Debt securities, available-for-sale		36
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Asset-backed securities | Retained Business
Assets
Debt securities, available-for-sale	$ 79	$ 155
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Minimum | Measurement Input, Withdrawal Rate
Liabilities:
Insurance liability, measurement input	0.77	0.77
Recurring | Level 3 | Valuation Technique, Discounted Cash Flow | Maximum  | Measurement Input, Withdrawal Rate
Liabilities:
Insurance liability, measurement input	1	1
Recurring | Level 3 | Valuation, market approach | Corporate Securities | Retained Business
Assets
Debt securities, available-for-sale	$ 32
Recurring | Level 3 | Valuation, market approach | Foreign corporate private securities | Retained Business
Assets
Debt securities, available-for-sale	9
Recurring | Level 3 | Valuation, market approach | Asset-backed securities | Retained Business
Assets
Debt securities, available-for-sale	134
Recurring | Level 3 | Valuation, market approach | Residential mortgage loans | Retained Business
Assets
Mortgage and other loans	107
Recurring | Level 3 | Valuation, market approach | Commercial mortgage-backed securities | Retained Business
Assets
Mortgage and other loans	78	$ 35
Recurring | Level 3 | Valuation Technique, Level Yield | Residential mortgage loans | Retained Business
Assets
Mortgage and other loans	$ 237	$ 161