Investments (Details 14) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Credit Quality Indicators [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer	$ 2,312,167,000	$ 1,003,524,000
High Investment Grade [Member]
Credit Quality Indicators [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer	1,235,605,000	252,333,000
Investment Grade [Member]
Credit Quality Indicators [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer	834,494,000	526,608,000
Average [Member]
Credit Quality Indicators [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer	132,607,000	105,177,000
Watch List [Member]
Credit Quality Indicators [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer	76,463,000	91,037,000
In Or Near Default [Member]
Credit Quality Indicators [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer	$ 32,998,000	$ 28,369,000