INVESTMENTS - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 USD ($) investment	Jun. 30, 2022 USD ($) investment	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Schedule of Investments [Line Items]
Held to maturity securities transferred to available for sale securities, number of investments | investment		0	0
Equity securities, FV-NI, unrealized gain (loss)	$ (16)	$ (21)
Transitional real estate loan commitments	792	792
Middle market loan program unfunded amount	26	26			$ 28
Middle market loan commitments	726	726
Amortized Cost	17,441	17,441			19,063
Loan Commitments, Allowance for Credit Loss	20	20
Limited partnerships investment commitments	$ 2,300	$ 2,300
Percentage that the lending policy requires that the fair value of the securities received as collateral be of the fair value of the loaned securities	102.00%	102.00%
Percentage that the lending policy requires that the fair value of the unrestricted cash received as collateral be of the fair value of the loaned securities	100.00%	100.00%
Securities Lending, Securities Received as Collateral	$ 5,000	$ 5,000			6,800
Repurchase Agreements and Repurchase-to-Maturity Transactions Outstanding	0	0			0
Credit allowance	225	225			192
Nonaccrual loans, interest income	0	0
Financing receivable, before allowance for credit loss	13,571	13,571			13,688
Transitional real estate loans
Schedule of Investments [Line Items]
Nonaccrual loans, no allowance	218	218
Financing receivable, before allowance for credit loss	6,775	6,775
Middle market loans
Schedule of Investments [Line Items]
Nonaccrual loans, no allowance	0	0
Financing receivable, before allowance for credit loss	5,040	5,040
Transitional real estate loans
Schedule of Investments [Line Items]
Credit allowance	76	76	$ 53	$ 65	54	$ 52	$ 68
Financing receivable, before allowance for credit loss	6,775	6,775			$ 6,509
Transitional real estate loans | Potential Foreclosure or Deed-in-lieu Foreclosure
Schedule of Investments [Line Items]
Amortized cost of financing receivable in anticipation of foreclosure		626
Credit allowance	21	21
Financing receivable, before allowance for credit loss	365	365
Zero-credit-loss expectation | Japan government and agencies
Schedule of Investments [Line Items]
Amortized Cost	$ 16,600	$ 16,600
CALIFORNIA | Commercial Mortgage and Transitional Real Estate Loans | Mortgages
Schedule of Investments [Line Items]
Concentration Risk, Percentage		20.00%
TEXAS | Commercial Mortgage and Transitional Real Estate Loans | Mortgages
Schedule of Investments [Line Items]
Concentration Risk, Percentage		12.00%
FLORIDA | Commercial Mortgage and Transitional Real Estate Loans | Mortgages
Schedule of Investments [Line Items]
Concentration Risk, Percentage		10.00%