Investments (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net Investment Income:
Investment income, before expense	$ 932	$ 1,038	$ 1,931	$ 2,069
Investment expense	(34)	(54)	(74)	(102)
Net investment income	898	984	1,857	1,967
Fixed income securities
Net Investment Income:
Investment income, before expense	584	740	1,289	1,502
Equity securities
Net Investment Income:
Investment income, before expense	35	39	63	64
Mortgage loans
Net Investment Income:
Investment income, before expense	71	93	152	191
Limited partnership interests
Net Investment Income:
Investment income, before expense	195	126	337	233
Short-term investments
Net Investment Income:
Investment income, before expense	3	1	4	3
Other
Net Investment Income:
Investment income, before expense	$ 44	$ 39	$ 86	$ 76