CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Premiums, reinsurance ceded	$ 149	$ 158	$ 167
Contract charges, reinsurance ceded	191	189	189
Contract benefits, reinsurance ceded	208	224	237
Interest credited to contractholder funds, reinsurance ceded	$ 46	$ 46	$ 40