Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	$ (883)	$ (2,775)	$ 918
Other comprehensive income (loss):
Unrealized investment gains (losses), net of related offsets	590	(535)	(1,681)
Unrealized gains (losses) on derivatives	(166)	27	89
Foreign currency translation adjustments	9	(3)	(29)
Other comprehensive income (loss), before income tax	433	(511)	(1,621)
Income tax (expense) benefit related to items of other comprehensive income (loss)	156	165	593
Other comprehensive income (loss), net of income tax	589	(346)	(1,028)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ (294)	$ (3,121)	$ (110)