Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$ 692	$ 727	$ 442	$ 831
Transfer to net assets held for sale
Other comprehensive income (loss), before reclassifications	308	(610)	584	(706)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	38	(9)	64	(1)
Other Comprehensive Income (loss), net of tax	270	(601)	520	(705)
Accumulated other comprehensive income (loss), ending balance	962	126	962	126
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	(22)	5	(35)	2
Tax (expense) benefit on other comprehensive income (loss)	(124)	316	(263)	341
Net unrealized gains (losses) on investments with OTTI losses [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	33	34	26	20
Transfer to net assets held for sale			(5)
Other comprehensive income (loss), before reclassifications	2	(8)	14	6
Amounts reclassified from accumulated other comprehensive income (loss), net of tax
Other Comprehensive Income (loss), net of tax	2	(8)	14	6
Accumulated other comprehensive income (loss), ending balance	35	26	35	26
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
Tax (expense) benefit on other comprehensive income (loss)	(1)	4	(7)	(3)
Net unrealized gains (losses) on other investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	912	1,309	692	1,371
Transfer to net assets held for sale			(17)
Other comprehensive income (loss), before reclassifications	257	(589)	521	(638)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(13)	(4)	14	9
Other Comprehensive Income (loss), net of tax	270	(585)	507	(647)
Accumulated other comprehensive income (loss), ending balance	1,182	724	1,182	724
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	6	3	(8)	(3)
Tax (expense) benefit on other comprehensive income (loss)	(146)	314	(273)	349
Net unrealized gains (losses) on discontinued operations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	30
Transfer to net assets held for sale			22
Other comprehensive income (loss), before reclassifications	7		15
Amounts reclassified from accumulated other comprehensive income (loss), net of tax
Other Comprehensive Income (loss), net of tax	7		15
Accumulated other comprehensive income (loss), ending balance	37		37
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
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	(425)	(716)	(426)	(721)
Transfer to net assets held for sale
Other comprehensive income (loss), before reclassifications
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	51	(5)	50	(10)
Other Comprehensive Income (loss), net of tax	(51)	5	(50)	10
Accumulated other comprehensive income (loss), ending balance	(476)	(711)	(476)	(711)
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	(28)	2	(27)	5
Tax (expense) benefit on other comprehensive income (loss)	28	(2)	27	(5)
Cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	142	100	150	161
Transfer to net assets held for sale
Other comprehensive income (loss), before reclassifications	42	(13)	34	(74)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax
Other Comprehensive Income (loss), net of tax	42	(13)	34	(74)
Accumulated other comprehensive income (loss), ending balance	184	87	184	87
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
Tax (expense) benefit on other comprehensive income (loss)