Investments (Details 7) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Investments [Abstract]
Net unrealized gains related to changes in valuation of fixed income securities subsequent to impairment measurement date	$ 221	$ 233
Other-than 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	(134)	(123)
Municipal
Other-than 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	(8)	(8)
Asset-backed securities (“ABS”)
Other-than 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	(15)	(2)
Residential mortgage-backed securities (“RMBS”)
Other-than 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	(105)	(108)
Commercial mortgage-backed securities (“CMBS”)
Other-than 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	$ (6)	$ (5)