Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Comprehensive Income
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 118	$ 230	$ 146	$ 375
Total comprehensive income	351	(255)	621	3
Other comprehensive income (loss):
Total other comprehensive income	233	(485)	475	(372)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Other comprehensive income (loss):
Change in net unrealized gain / loss on securities	228	(467)	454	(364)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Other comprehensive income (loss):
Change in net gain / loss on cash-flow hedging instruments	$ 4	$ (18)	$ 20	$ (8)