FAIR VALUE DISCLOSURES - Quantitative Information about Level 3 (Details) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2024 USD ($)	Sep. 30, 2023	Dec. 31, 2023 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liability for market risk benefits	$ 12,814		$ 14,612
Assets for market risk benefits	818		591
Level 3 \| Discounted cash flow \| Alliance Bernstein
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
AB Contingent consideration payable	$ 254		$ 253
Level 3 \| Discounted cash flow \| Discount Rate \| Minimum \| Alliance Bernstein
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected revenue growth and discount rate	0.019		0.019
Level 3 \| Discounted cash flow \| Discount Rate \| Maximum \| Alliance Bernstein
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected revenue growth and discount rate	0.104		0.104
Level 3 \| Discounted cash flow \| Discount Rate \| Weighted Average \| Alliance Bernstein
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected revenue growth and discount rate	0.046		0.046
Level 3 \| Discounted cash flow \| Expected Revenue Growth Rate \| Minimum \| Alliance Bernstein
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected revenue growth and discount rate	0.020		0.020
Level 3 \| Discounted cash flow \| Expected Revenue Growth Rate \| Maximum \| Alliance Bernstein
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected revenue growth and discount rate	0.293		0.839
Level 3 \| Discounted cash flow \| Expected Revenue Growth Rate \| Weighted Average \| Alliance Bernstein
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Expected revenue growth and discount rate	0.079		0.103
Level 3 \| Corporate \| Matrix pricing model
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of fixed maturities AFS	$ 350		$ 373
Level 3 \| Corporate \| Matrix pricing model \| Spread over Benchmark \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0020		0.0020
Level 3 \| Corporate \| Matrix pricing model \| Spread over Benchmark \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0270		0.0747
Level 3 \| Corporate \| Matrix pricing model \| Spread over Benchmark \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0145		0.0181
Level 3 \| Corporate \| Market comparable companies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of fixed maturities AFS	$ 1,172		$ 979
Level 3 \| Corporate \| Market comparable companies \| EBITDA Multiples \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	3.3		3.3
Level 3 \| Corporate \| Market comparable companies \| EBITDA Multiples \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	30.5		29.0
Level 3 \| Corporate \| Market comparable companies \| EBITDA Multiples \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	13.5		13.6
Level 3 \| Corporate \| Market comparable companies \| Discount Rate \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.000		0.000
Level 3 \| Corporate \| Market comparable companies \| Discount Rate \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.192		0.228
Level 3 \| Corporate \| Market comparable companies \| Discount Rate \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.038		0.039
Level 3 \| Corporate \| Market comparable companies \| Cash Flow Multiples \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.8		0.8
Level 3 \| Corporate \| Market comparable companies \| Cash Flow Multiples \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	9.3		10.0
Level 3 \| Corporate \| Market comparable companies \| Cash Flow Multiples \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	6.2		6.3
Level 3 \| Corporate \| Market comparable companies \| Loan to Value \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.000		0.034
Level 3 \| Corporate \| Market comparable companies \| Loan to Value \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.614		0.610
Level 3 \| Corporate \| Market comparable companies \| Loan to Value \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.140		0.138
Level 3 \| Trading Securities, at Fair Value \| Discounted cash flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of fixed maturities AFS	$ 61		$ 61
Discount years	7 years	7 years
Level 3 \| Trading Securities, at Fair Value \| Discounted cash flow \| Earnings/Revenue Multiple
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	9.1		9.1
Level 3 \| Trading Securities, at Fair Value \| Discounted cash flow \| Discount Factor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.100		0.1000
Level 3 \| Other equity investments \| Discounted cash flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of fixed maturities AFS	$ 2		$ 2
Level 3 \| Other equity investments \| Discounted cash flow \| Earnings/Revenue Multiple \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	3.9		3.9
Level 3 \| Other equity investments \| Discounted cash flow \| Earnings/Revenue Multiple \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	7.0		8.4
Level 3 \| Other equity investments \| Discounted cash flow \| Earnings/Revenue Multiple \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	5.9		6.5
Level 3 \| Purchased MRB asset \| Discounted cash flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of fixed maturities AFS	$ 8,337		$ 9,427
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Lapse Rate \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0021		0.0021
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Lapse Rate \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.1238		0.1238
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Lapse Rate \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0196		0.0179
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Withdrawal Rate \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0007		0.0007
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Withdrawal Rate \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.1497		0.1497
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Withdrawal Rate \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0050		0.0046
Level 3 \| Purchased MRB asset \| Discounted cash flow \| GMIB Utilization Rate \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0004		0.0004
Level 3 \| Purchased MRB asset \| Discounted cash flow \| GMIB Utilization Rate \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.6621		0.6621
Level 3 \| Purchased MRB asset \| Discounted cash flow \| GMIB Utilization Rate \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0691		0.0744
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Non-Performance Risk \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0032		0.0035
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Non-Performance Risk \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0101		0.0097
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Non-Performance Risk \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0040		0.0045
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Volatility Rate - Equity \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.12		0.11
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Volatility Rate - Equity \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.28		0.28
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Volatility Rate - Equity \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.23		0.23
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Mortality \| Ages 0 - 40 \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0001		0.0001
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Mortality \| Ages 0 - 40 \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0018		0.0018
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Mortality \| Ages 0 - 40 \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0325		0.0307
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Mortality \| Ages 41 - 60 \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0007		0.0007
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Mortality \| Ages 41 - 60 \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0053		0.0053
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Mortality \| Ages 61 - 115 \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.0033		0.0033
Level 3 \| Purchased MRB asset \| Discounted cash flow \| Mortality \| Ages 61 - 115 \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percentage measurement input of equity securities	0.4200		0.4200
Level 3 \| Direct MRB \| Discounted cash flow
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Direct MRB	$ 11,996		$ 14,021
Level 3 \| Direct MRB \| Discounted cash flow \| Lapse Rate \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0021		0.0021
Level 3 \| Direct MRB \| Discounted cash flow \| Lapse Rate \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.2937		0.2937
Level 3 \| Direct MRB \| Discounted cash flow \| Lapse Rate \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0320		0.0307
Level 3 \| Direct MRB \| Discounted cash flow \| Withdrawal Rate \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0000		0.0000
Level 3 \| Direct MRB \| Discounted cash flow \| Withdrawal Rate \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.1497		0.1497
Level 3 \| Direct MRB \| Discounted cash flow \| Withdrawal Rate \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0067		0.0064
Level 3 \| Direct MRB \| Discounted cash flow \| Non-Performance Risk
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0117		0.0118
Level 3 \| Direct MRB \| Discounted cash flow \| Non-Performance Risk \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0117		0.0118
Level 3 \| Direct MRB \| Discounted cash flow \| Mortality \| Ages 0 - 40 \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0001		0.0001
Level 3 \| Direct MRB \| Discounted cash flow \| Mortality \| Ages 0 - 40 \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0018		0.0018
Level 3 \| Direct MRB \| Discounted cash flow \| Mortality \| Ages 0 - 40 \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0267		0.0250
Level 3 \| Direct MRB \| Discounted cash flow \| Mortality \| Ages 41 - 60 \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0007		0.0007
Level 3 \| Direct MRB \| Discounted cash flow \| Mortality \| Ages 41 - 60 \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0053		0.0053
Level 3 \| Direct MRB \| Discounted cash flow \| Mortality \| Ages 61 - 115 \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0033		0.0033
Level 3 \| Direct MRB \| Discounted cash flow \| Mortality \| Ages 61 - 115 \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.4200		0.4200
Level 3 \| Direct MRB \| Discounted cash flow \| Annuitization Rate \| Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0004		0.0004
Level 3 \| Direct MRB \| Discounted cash flow \| Annuitization Rate \| Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	1.0000		1.0000
Level 3 \| Direct MRB \| Discounted cash flow \| Annuitization Rate \| Weighted Average
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Measurement input of servicing liability	0.0515		0.0538