Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$ 143	$ 962	$ 400	$ 442
Transfer to net assets held for sale				0
Other comprehensive income (loss), before reclassifications	(118)	(136)	(385)	448
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	(35)	53	(45)	117
Other comprehensive income (loss) after tax (expense) benefit	(83)	(189)	(340)	331
Accumulated other comprehensive income (loss), ending balance	60	773	60	773
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	19	(33)	31	(68)
Tax (expense) benefit on other comprehensive income (loss)	18	87	113	(176)
Net unrealized gains (losses) on investments with OTTI losses [Member)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	31	35	36	26
Transfer to net assets held for sale				(5)
Other comprehensive income (loss), before reclassifications	2	1	(3)	15
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0	0	0
Other comprehensive income (loss) after tax (expense) benefit	2	1	(3)	15
Accumulated other comprehensive income (loss), ending balance	33	36	33	36
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Tax (expense) benefit on other comprehensive income (loss)	(1)	(1)	1	(8)
Net unrealized gains (losses) on other investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	689	1,182	942	692
Transfer to net assets held for sale				(17)
Other comprehensive income (loss), before reclassifications	(67)	(59)	(318)	462
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	(31)	24	(29)	38
Other comprehensive income (loss) after tax (expense) benefit	(36)	(83)	(289)	424
Accumulated other comprehensive income (loss), ending balance	653	1,099	653	1,099
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	17	(12)	22	(20)
Tax (expense) benefit on other comprehensive income (loss)	21	64	140	(209)
Accumulated Net Unrealized Gains Losses on discontinued operations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance		37		0
Transfer to net assets held for sale				22
Other comprehensive income (loss), before reclassifications		(3)		12
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit		34		34
Other comprehensive income (loss) after tax (expense) benefit		(37)		(22)
Accumulated other comprehensive income (loss), ending balance		0		0
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)		(23)		(23)
Tax (expense) benefit on other comprehensive income (loss)		25		15
Pension and postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(585)	(476)	(633)	(426)
Transfer to net assets held for sale				0
Other comprehensive income (loss), before reclassifications	0	(2)	36	(2)
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	(4)	(5)	(16)	45
Other comprehensive income (loss) after tax (expense) benefit	4	3	52	(47)
Accumulated other comprehensive income (loss), ending balance	(581)	(473)	(581)	(473)
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	2	2	9	(25)
Tax (expense) benefit on other comprehensive income (loss)	(2)	(1)	(28)	26
Cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	8	184	55	150
Transfer to net assets held for sale				0
Other comprehensive income (loss), before reclassifications	(53)	(73)	(100)	(39)
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0	0	0
Other comprehensive income (loss) after tax (expense) benefit	(53)	(73)	(100)	(39)
Accumulated other comprehensive income (loss), ending balance	(45)	111	(45)	111
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Tax (expense) benefit on other comprehensive income (loss)	$ 0	$ 0	$ 0	$ 0