INSURANCE LIABILITIES - Summary of No-Lapse Guarantee Liabilities and Other Policyholder's Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Direct Liability
Balance, beginning of period	$ 8,882	$ 7,035
Paid Guaranteed Benefits	(133)	(123)
Balance, end of period	8,706	9,016
Direct Liability
Direct Liability
Balance, beginning of period	686	1,197
Paid Guaranteed Benefits	(8)
Other changes in reserves	18	93
Balance, end of period	696	1,290
Reinsurance Ceded
Direct Liability
Balance, beginning of period	(664)	(609)
Paid Guaranteed Benefits	0
Other changes in reserves	(11)	0
Balance, end of period	(675)	(609)
Net
Direct Liability
Balance, beginning of period	22	588
Paid Guaranteed Benefits	(8)
Other changes in reserves	7	93
Balance, end of period	$ 21	$ 681