REINSURANCE AGREEMENTS - Effect of reinsurance (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Premiums:
Direct premiums						$ 880	$ 850	$ 818
Reinsurance assumed						195	206	207
Reinsurance ceded						(171)	(176)	(173)
Premiums	$ 208	$ 225	$ 232	$ 457	$ 665	904	880	852
Policy charges and fee income ceded						718	640	645
Policyholders’ Benefits Ceded						$ 694	$ 942	$ 527