Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Comprehensive Income
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (40)	$ 216	$ 338	$ 539
Other Comprehensive Income (Loss), Net of Tax	701	646	831	1,229
Total comprehensive income	661	862	1,169	1,768
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Comprehensive Income
Other Comprehensive Income (Loss), Net of Tax	342	636	479	1,158
Accumulated Other-than-Temporary Impairment [Member]
Comprehensive Income
Other Comprehensive Income (Loss), Net of Tax	1	5	0	(3)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Comprehensive Income
Other Comprehensive Income (Loss), Net of Tax	(1)	16	(19)	70
Accumulated Translation Adjustment [Member]
Comprehensive Income
Other Comprehensive Income (Loss), Net of Tax	5	(19)	7	(13)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Comprehensive Income
Other Comprehensive Income (Loss), Net of Tax	$ 354	$ 8	$ 364	$ 17