Investments- Other-than-temporary losses included in AOCI (Details 7) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Investments [Abstract]
Net unrealized gains related to changes in valuation of fixed income securities subsequent to impairment measurement date	$ 134	$ 138
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(73)	(74)
Municipal
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(5)	(5)
Corporate
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(5)	(2)
ABS
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(11)	(12)
RMBS
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(45)	(49)
CMBS
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	$ (7)	$ (6)