Equity Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			$ 4,030
Total other comprehensive loss	$ (77)	$ (281)	(277)	$ (373)
Ending Balance	4,057		4,057
Accumulated net unrealized investment gain (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,160	2,030	1,358	2,121
Other comprehensive income (loss) before reclassifications	50	(81)	(39)	(57)
Amounts reclassified from other comprehensive loss	(125)	(199)	(234)	(314)
Total other comprehensive loss	(75)	(280)	(273)	(371)
Ending Balance	1,085	1,750	1,085	1,750
Accumulated other comprehensive income (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	47	(389)	49	(388)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from other comprehensive loss	(2)	(1)	(4)	(2)
Total other comprehensive loss	(2)	(1)	(4)	(2)
Ending Balance	45	(390)	45	(390)
Accumulated other comprehensive income [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,207	1,641	1,407	1,733
Other comprehensive income (loss) before reclassifications	50	(81)	(39)	(57)
Amounts reclassified from other comprehensive loss	(127)	(200)	(238)	(316)
Total other comprehensive loss	(77)	(281)	(277)	(373)
Ending Balance	$ 1,130	$ 1,360	$ 1,130	$ 1,360