Investments (Details 12) (USD $) In Millions, unless otherwise specified																											12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Office buildings	Dec. 31, 2012 Office buildings	Dec. 31, 2013 Apartment complex	Dec. 31, 2012 Apartment complex	Dec. 31, 2013 Retail	Dec. 31, 2012 Retail	Dec. 31, 2013 Warehouse	Dec. 31, 2012 Warehouse	Dec. 31, 2013 Other	Dec. 31, 2012 Other	Dec. 31, 2013 California	Dec. 31, 2012 California	Dec. 31, 2013 Illinois	Dec. 31, 2012 Illinois	Dec. 31, 2013 New Jersey	Dec. 31, 2012 New Jersey	Dec. 31, 2013 Texas	Dec. 31, 2012 Texas	Dec. 31, 2013 New York	Dec. 31, 2012 New York	Dec. 31, 2013 Florida	Dec. 31, 2012 Florida	Dec. 31, 2013 District of Columbia	Dec. 31, 2012 District of Columbia	Dec. 31, 2013 Mortgage loans, not in foreclosure loan	Dec. 31, 2013 Mortgage loans, not in foreclosure 2014 loan	Dec. 31, 2013 Mortgage loans, not in foreclosure 2015 loan	Dec. 31, 2013 Mortgage loans, not in foreclosure 2016 loan	Dec. 31, 2013 Mortgage loans, not in foreclosure 2017 loan	Dec. 31, 2013 Mortgage loans, not in foreclosure Thereafter loan
Investments
Threshold percentage of mortgage loans to total carrying value	5.00%
Mortgage Loans on Real Estate
Percentage of mortgage portfolio carrying value	100.00%	100.00%	26.50%	26.60%	23.20%	20.60%	21.00%	22.70%	18.00%	19.70%	11.30%	10.40%	23.00%	23.60%	10.00%	8.10%	6.80%	6.20%	6.30%	6.40%	6.00%	6.40%	5.70%	4.70%	5.30%	3.80%	100.00%	7.10%	13.30%	11.60%	10.10%	57.90%
Number of mortgage loans																											353	23	38	46	42	204
Mortgage loans	$ 4,721	$ 6,570																									$ 4,721	$ 336	$ 628	$ 548	$ 475	$ 2,734