Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	May 31, 2018	Sep. 30, 2017
Net income (loss)	$ 67	$ 83	$ 124	$ 94	$ 270
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent	(49)	32		(430)	238
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent	0	(7)		(18)	(16)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	0	0		1	0
OCI, net of tax	(49)	25	(122)	(447)	222
Comprehensive income	$ 18	108	2	(353)	492
Accumulated Net Unrealized Investment Gain (Loss)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent			(124)
OCI, net of tax		32		(430)	238
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax			$ 2
OCI, net of tax		$ 0		$ 1	$ 0