DAC AND POLICYHOLDER BONUS INTEREST CREDITS - Rollforward of DAC Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year	$ 4,225
Balance, beginning of year	4,222	$ 4,959	$ 4,443
Capitalization of commissions, sales and issue expenses	564	646	591
Amortization:
Impact of assumptions updates and model changes	(866)	77	165
All other	(467)	(597)	(616)
Total amortization	(1,333)	(520)	(451)
Change in unrealized investment gains (losses)	360	(863)	376
Balance, end of year	3,816	4,225
Balance, end of Year	3,816	4,222	4,959
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	$ 4,222	4,222	4,443
Accounting Standards Update 2016-13
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Balance, beginning of year		3
Amortization:
Balance, end of Year			3
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs		$ 3	$ 3