Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$ 442	$ 831
Transfer to net assets held for sale
Other comprehensive income (loss), before reclassifications	276	(96)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	26	8
Other Comprehensive Income (loss), net of tax	250	(104)
Accumulated other comprehensive income (loss), ending balance	692	727
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	(13)	(3)
Tax (expense) benefit on other comprehensive income (loss)	(139)	25
Net unrealized gains (losses) on investments with OTTI losses [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	26	20
Transfer to net assets held for sale	(5)
Other comprehensive income (loss), before reclassifications	12	14
Amounts reclassified from accumulated other comprehensive income (loss), net of tax
Other Comprehensive Income (loss), net of tax	12	14
Accumulated other comprehensive income (loss), ending balance	33	34
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
Tax (expense) benefit on other comprehensive income (loss)	(6)	(7)
Net unrealized gains (losses) on other investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	692	1,371
Transfer to net assets held for sale	(17)
Other comprehensive income (loss), before reclassifications	264	(49)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	27	13
Other Comprehensive Income (loss), net of tax	237	(62)
Accumulated other comprehensive income (loss), ending balance	912	1,309
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	(14)	(6)
Tax (expense) benefit on other comprehensive income (loss)	(127)	35
Net unrealized gains (losses) on discontinued operations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance
Transfer to net assets held for sale	22
Other comprehensive income (loss), before reclassifications	8
Amounts reclassified from accumulated other comprehensive income (loss), net of tax
Other Comprehensive Income (loss), net of tax	8
Accumulated other comprehensive income (loss), ending balance	30
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
Tax (expense) benefit on other comprehensive income (loss)	(5)
Pension and postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(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	(1)	(5)
Other Comprehensive Income (loss), net of tax	1	5
Accumulated other comprehensive income (loss), ending balance	(425)	(716)
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	1	3
Tax (expense) benefit on other comprehensive income (loss)	(1)	(3)
Cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	150	161
Transfer to net assets held for sale
Other comprehensive income (loss), before reclassifications	(8)	(61)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax
Other Comprehensive Income (loss), net of tax	(8)	(61)
Accumulated other comprehensive income (loss), ending balance	142	100
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)
Tax (expense) benefit on other comprehensive income (loss)