Investments (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net investment income
Investment income, before expense	$ 2,593	$ 2,711	$ 2,739
Investment expense	(108)	(114)	(102)
Net investment income	2,485	2,597	2,637
Fixed income securities
Net investment income
Investment income, before expense	1,947	2,084	2,264
Mortgage loans
Net investment income
Investment income, before expense	345	345	345
Equity securities
Net investment income
Investment income, before expense	12	9	7
Limited partnership interests
Net investment income
Investment income, before expense	175	159	49
Short-term investments
Net investment income
Investment income, before expense	2	2	3
Policy loans
Net investment income
Investment income, before expense	49	51	53
Other
Net investment income
Investment income, before expense	$ 63	$ 61	$ 18