Equity Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			$ 4,030
Total other comprehensive income (loss)	$ (207)	$ 253	(484)	$ (120)
Ending Balance	4,176		4,176
Accumulated net unrealized investment gain (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,085	1,750	1,358	2,121
Other comprehensive income (loss) before reclassifications	33	(107)	(6)	(164)
Amounts reclassified from other comprehensive income (loss)	(238)	(70)	(472)	(384)
Total other comprehensive income (loss)	(205)	(177)	(478)	(548)
Ending Balance	880	1,573	880	1,573
Accumulated other comprehensive income (loss) [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	45	(390)	49	(388)
Other comprehensive income (loss) before reclassifications	0	6	0	6
Amounts reclassified from other comprehensive income (loss)	(2)	424	(6)	422
Total other comprehensive income (loss)	(2)	430	(6)	428
Ending Balance	43	40	43	40
Accumulated other comprehensive income [Member]
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,130	1,360	1,407	1,733
Other comprehensive income (loss) before reclassifications	33	(101)	(6)	(158)
Amounts reclassified from other comprehensive income (loss)	(240)	354	(478)	38
Total other comprehensive income (loss)	(207)	253	(484)	(120)
Ending Balance	$ 923	$ 1,613	$ 923	$ 1,613