INVESTMENTS (TRADING SECURITIES) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net Realized and Unrealized Gain (Loss) on Trading Securities [Abstract]
Net investment gains (losses) recognized during the period on securities held at the end of the period	$ 45	$ 7	$ 153	$ 126
Net investment gains (losses) recognized on securities sold during the period	10	1	35	(9)
Unrealized and realized gains (losses) on trading securities arising during the period	55	8	188	117
Interest and dividend income from trading securities	54	34	143	82
Net investment income (loss) from trading securities	$ 109	$ 42	$ 331	$ 199