INVESTMENTS - Loan-To-Value (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 37,569,217	$ 35,650,926
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,990,906	6,081,261
Year two, fiscal year before current fiscal year	6,284,223	6,845,839
Year three, two years before current fiscal year	6,914,605	809,254
Year four, three years before current fiscal year	649,280	1,529,897
Year five, four years before current fiscal year	1,472,474	1,260,593
Year six, five years before current fiscal year	1,066,050	717,304
Prior	2,089,968	1,586,632
Total	20,467,506	18,830,780
Carrying value loan-to-value 70% and less | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,990,906	5,677,763
Year two, fiscal year before current fiscal year	5,918,474	4,971,346
Year three, two years before current fiscal year	5,106,903	650,825
Year four, three years before current fiscal year	483,676	1,211,523
Year five, four years before current fiscal year	1,334,915	1,061,566
Year six, five years before current fiscal year	857,463	699,144
Prior	2,038,568	1,586,632
Total	17,730,905	15,858,799
Carrying value loan-to-value 71% - 90% | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	403,498
Year two, fiscal year before current fiscal year	365,749	1,758,748
Year three, two years before current fiscal year	1,589,107	123,343
Year four, three years before current fiscal year	93,626	215,050
Year five, four years before current fiscal year	93,824	18,885
Year six, five years before current fiscal year	52,158	0
Prior	0	0
Total	2,194,464	2,519,524
Carrying value loan-to-value over 90% | Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	0
Year two, fiscal year before current fiscal year	0	115,745
Year three, two years before current fiscal year	218,595	35,086
Year four, three years before current fiscal year	71,978	103,324
Year five, four years before current fiscal year	43,735	180,142
Year six, five years before current fiscal year	156,429	18,160
Prior	51,400	0
Total	$ 542,137	$ 452,457