INVESTMENTS - Mortgage Loans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 62
Balance, end of period	53	$ 74
Commercial mortgage loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	57	77
Current-period provision for expected credit losses	(10)	(7)
Write-offs charged against the allowance	0	0
Recoveries of amounts previously written off	0	0
Net change in allowance	(10)	(7)
Balance, end of period	47	70
Agricultural mortgage loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	5	4
Current-period provision for expected credit losses	1	0
Write-offs charged against the allowance	0	0
Recoveries of amounts previously written off	0	0
Net change in allowance	1	0
Balance, end of period	$ 6	$ 4