Accumulated Other Comprehensive Income (Loss) by Component (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	$ 442	$ 831
Change due to sale of subsidiaries	0
Other comprehensive income (loss), before reclassifications	8	(388)
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	50	1
Other comprehensive income (loss) after tax (expense) benefit	(42)	(389)
Accumulated other comprehensive income (loss), ending balance	400	442
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	(26)	1
Tax (expense) benefit on other comprehensive income (loss)	(4)	203
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
Change due to sale of subsidiaries	(5)
Other comprehensive income (loss), before reclassifications	15	6
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0
Other comprehensive income (loss) after tax (expense) benefit	15	6
Accumulated other comprehensive income (loss), ending balance	36	26
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0
Tax (expense) benefit on other comprehensive income (loss)	(8)	(3)
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
Change due to sale of subsidiaries	(17)
Other comprehensive income (loss), before reclassifications	295	(658)
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	28	21
Other comprehensive income (loss) after tax (expense) benefit	267	(679)
Accumulated other comprehensive income (loss), ending balance	942	692
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	(10)	(10)
Tax (expense) benefit on other comprehensive income (loss)	(122)	364
Accumulated Net Unrealized Gains Losses on discontinued operations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	0
Change due to sale of subsidiaries	22
Other comprehensive income (loss), before reclassifications	12
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	34
Other comprehensive income (loss) after tax (expense) benefit	(22)
Accumulated other comprehensive income (loss), ending balance	0
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	(23)
Tax (expense) benefit on other comprehensive income (loss)	15
Pension and postretirement benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	(426)	(721)
Change due to sale of subsidiaries	0
Other comprehensive income (loss), before reclassifications	(219)	275
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	(12)	(20)
Other comprehensive income (loss) after tax (expense) benefit	(207)	295
Accumulated other comprehensive income (loss), ending balance	(633)	(426)
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	7	11
Tax (expense) benefit on other comprehensive income (loss)	111	(158)
Cumulative foreign currency translation adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance	150	161
Change due to sale of subsidiaries	0
Other comprehensive income (loss), before reclassifications	(95)	(11)
Amounts reclassified from accumulated other comprehensive income (loss) after tax (expense) benefit	0	0
Other comprehensive income (loss) after tax (expense) benefit	(95)	(11)
Accumulated other comprehensive income (loss), ending balance	55	150
Tax (expense) benefit on amounts reclassified from accumulated other comprehensive income (loss)	0	0
Tax (expense) benefit on other comprehensive income (loss)	$ 0	$ 0