INVESTMENTS - Nonaccrual Loans (Details) - USD ($) $ in Millions	Mar. 31, 2024		Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Total	$ 12,592		$ 12,801
Total, nonaccrual status	910		718
Total, 90 days or more past due and still accruing	0		0
Transitional real estate loans
Financing Receivable, Past Due [Line Items]
Total	6,078		6,114
Total, nonaccrual status	829		633
Commercial mortgage loans
Financing Receivable, Past Due [Line Items]
Total	1,653		1,709
Total, nonaccrual status	55		0
Middle market loans
Financing Receivable, Past Due [Line Items]
Total	4,586		4,677
Total, nonaccrual status	26		85
Other loans
Financing Receivable, Past Due [Line Items]
Total	275		301
Total, nonaccrual status	0		0
Current
Financing Receivable, Past Due [Line Items]
Total	11,585		12,050
Current | Transitional real estate loans
Financing Receivable, Past Due [Line Items]
Total	5,152		5,481
Current | Commercial mortgage loans
Financing Receivable, Past Due [Line Items]
Total	1,598		1,676
Current | Middle market loans
Financing Receivable, Past Due [Line Items]
Total	4,560		4,592
Current | Other loans
Financing Receivable, Past Due [Line Items]
Total	275		301
Less Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	97		141
Less Than 90 Days Past Due | Transitional real estate loans
Financing Receivable, Past Due [Line Items]
Total	97		108
Less Than 90 Days Past Due | Commercial mortgage loans
Financing Receivable, Past Due [Line Items]
Total	0		33
Less Than 90 Days Past Due | Middle market loans
Financing Receivable, Past Due [Line Items]
Total	0		0
Less Than 90 Days Past Due | Other loans
Financing Receivable, Past Due [Line Items]
Total	0		0
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Total	910	[1]	610	[2]
90 Days or More Past Due | Transitional real estate loans
Financing Receivable, Past Due [Line Items]
Total	829	[1]	525	[2]
90 Days or More Past Due | Commercial mortgage loans
Financing Receivable, Past Due [Line Items]
Total	55	[1]	0	[2]
90 Days or More Past Due | Middle market loans
Financing Receivable, Past Due [Line Items]
Total	26	[1]	85	[2]
90 Days or More Past Due | Other loans
Financing Receivable, Past Due [Line Items]
Total	0	[1]	0	[2]
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total	1,007		751
Financial Asset, Past Due | Transitional real estate loans
Financing Receivable, Past Due [Line Items]
Total	926		633
Financial Asset, Past Due | Commercial mortgage loans
Financing Receivable, Past Due [Line Items]
Total	55		33
Financial Asset, Past Due | Middle market loans
Financing Receivable, Past Due [Line Items]
Total	26		85
Financial Asset, Past Due | Other loans
Financing Receivable, Past Due [Line Items]
Total	$ 0		$ 0

[1] As of March 31, 2024, there were no loans that were 90 days or more past due that continued to accrue interest.

[2] As of December 31, 2023, there were no loans that were 90 days or more past due that continued to accrue interest.