INVESTMENTS - Trading Securities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Net investment gains (losses) recognized during the period on securities held at the end of the period	$ (1)	$ 7	$ 86	$ 431
Net investment gains (losses) recognized on securities sold during the period	(5)	13	12	(10)
Unrealized and realized gains (losses) on trading securities	(6)	20	98	421
Interest and dividend income from trading securities	58	59	152	220
Net investment income (loss) from trading securities	$ 52	$ 79	$ 250	$ 641