INVESTMENTS - Amortized Cost of Loans by Credit Quality Indicator and Origination Year (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Amortized Cost Basis by Origination Year
Total	$ 549	$ 296
Residential mortgages:
Amortized Cost Basis by Origination Year
Current fiscal year	0
Fiscal year before current fiscal year	96
Two years before current fiscal year	18
Three years before current fiscal year	16
Four years before current fiscal year	1
Prior	0
Total	131	$ 0
Residential mortgages: | Performing
Amortized Cost Basis by Origination Year
Current fiscal year	0
Fiscal year before current fiscal year	96
Two years before current fiscal year	18
Three years before current fiscal year	16
Four years before current fiscal year	1
Prior	0
Total	131
Residential mortgages: | Nonperforming
Amortized Cost Basis by Origination Year
Current fiscal year	0
Fiscal year before current fiscal year	0
Two years before current fiscal year	0
Three years before current fiscal year	0
Four years before current fiscal year	0
Prior	0
Total	$ 0