Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$ 421	$ 692	$ 400	$ 442
Transfer to net assets held for sale				0
Other comprehensive income (loss), before reclassifications	(291)	308	(267)	584
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	(13)	38	(10)	64
Other comprehensive income (loss) after tax (expense) benefit	(278)	270	(257)	520
Accumulated other comprehensive income (loss), ending balance	143	962	143	962
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	9	(22)	12	(35)
Tax (expense) benefit on other comprehensive income (loss)	160	(124)	95	(263)
Net unrealized gains (losses) on investments with OTTI losses [Member)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	35	33	36	26
Transfer to net assets held for sale				(5)
Other comprehensive income (loss), before reclassifications	(4)	2	(5)	14
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0	0	0
Other comprehensive income (loss) after tax (expense) benefit	(4)	2	(5)	14
Accumulated other comprehensive income (loss), ending balance	31	35	31	35
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Tax (expense) benefit on other comprehensive income (loss)	2	(1)	2	(7)
Net unrealized gains (losses) on other investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	1,054	912	942	692
Transfer to net assets held for sale				(17)
Other comprehensive income (loss), before reclassifications	(372)	257	(251)	521
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	(7)	(13)	2	14
Other comprehensive income (loss) after tax (expense) benefit	(365)	270	(253)	507
Accumulated other comprehensive income (loss), ending balance	689	1,182	689	1,182
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	5	6	5	(8)
Tax (expense) benefit on other comprehensive income (loss)	181	(146)	119	(273)
Accumulated Net Unrealized Gains Losses on discontinued operations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance		30		0
Transfer to net assets held for sale				22
Other comprehensive income (loss), before reclassifications		7		15
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit		0		0
Other comprehensive income (loss) after tax (expense) benefit		7		15
Accumulated other comprehensive income (loss), ending balance		37		37
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)		0		0
Tax (expense) benefit on other comprehensive income (loss)		(5)		(10)
Pension and postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(627)	(425)	(633)	(426)
Transfer to net assets held for sale				0
Other comprehensive income (loss), before reclassifications	36	0	36	0
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	(6)	51	(12)	50
Other comprehensive income (loss) after tax (expense) benefit	42	(51)	48	(50)
Accumulated other comprehensive income (loss), ending balance	(585)	(476)	(585)	(476)
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	4	(28)	7	(27)
Tax (expense) benefit on other comprehensive income (loss)	(23)	28	(26)	27
Cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(41)	142	55	150
Transfer to net assets held for sale				0
Other comprehensive income (loss), before reclassifications	49	42	(47)	34
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0	0	0
Other comprehensive income (loss) after tax (expense) benefit	49	42	(47)	34
Accumulated other comprehensive income (loss), ending balance	8	184	8	184
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