Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net income	$ 282	$ 500	$ 677
Other Comprehensive Income (Loss), Net of Tax	129	(628)	647
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	411	(128)	1,324
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest	0	0	1
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	411	(128)	1,323
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	154	(615)
Other Comprehensive Income (Loss), Net of Tax			659
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Other Comprehensive Income (Loss), Net of Tax			(9)
Accumulated Translation Adjustment [Member]
Other Comprehensive Income (Loss), Net of Tax			$ (3)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	$ 0	$ 0