Investments (Credit Quality Indicators) (Details) (Commercial Mortgage and Agricultural Loans [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Debt Service Coverage Ratio, Greater than One Point Two X [Member] | Loan To Value Ratio Less Than Fifty Nine Point Nine Nine Percent [Member]
Financing Receivable	$ 262,918	$ 251,278
Debt Service Coverage Ratio, Greater than One Point Two X [Member] | Loan To Value Ratio Sixty Percent To Sixty Nine Point Nine Nine Percent [Member]
Financing Receivable	101,075	102,755
Debt Service Coverage Ratio, Greater than One Point Two X [Member] | Loan-to-Value Ratio, Seventy Percent To Seventy Nine Point Nine Nine Percent [Member]
Financing Receivable	29,634	31,712
Debt Service Coverage Ratio, Greater than One Point Two X [Member] | Loan-to-Value Ratio Greater than Eighty Percent [Member]
Financing Receivable	3,116	0
Debt Service Coverage Ratio, Greater than One Point Two X [Member] | Loan To Value Ratio Total [Member]
Financing Receivable	396,743	385,745
Debt Service Coverage Ratio, One Point Zero X to Less Than One Point Two X [Member] | Loan To Value Ratio Less Than Fifty Nine Point Nine Nine Percent [Member]
Financing Receivable	7,412	7,650
Debt Service Coverage Ratio, One Point Zero X to Less Than One Point Two X [Member] | Loan To Value Ratio Sixty Percent To Sixty Nine Point Nine Nine Percent [Member]
Financing Receivable	0	0
Debt Service Coverage Ratio, One Point Zero X to Less Than One Point Two X [Member] | Loan-to-Value Ratio, Seventy Percent To Seventy Nine Point Nine Nine Percent [Member]
Financing Receivable	0	2,247
Debt Service Coverage Ratio, One Point Zero X to Less Than One Point Two X [Member] | Loan-to-Value Ratio Greater than Eighty Percent [Member]
Financing Receivable	0	0
Debt Service Coverage Ratio, One Point Zero X to Less Than One Point Two X [Member] | Loan To Value Ratio Total [Member]
Financing Receivable	7,412	9,897
Debt Service Coverage Ratio, Less Than One Point Zero X [Member] | Loan To Value Ratio Less Than Fifty Nine Point Nine Nine Percent [Member]
Financing Receivable	1,551	1,865
Debt Service Coverage Ratio, Less Than One Point Zero X [Member] | Loan To Value Ratio Sixty Percent To Sixty Nine Point Nine Nine Percent [Member]
Financing Receivable	0	0
Debt Service Coverage Ratio, Less Than One Point Zero X [Member] | Loan-to-Value Ratio, Seventy Percent To Seventy Nine Point Nine Nine Percent [Member]
Financing Receivable	0	0
Debt Service Coverage Ratio, Less Than One Point Zero X [Member] | Loan-to-Value Ratio Greater than Eighty Percent [Member]
Financing Receivable	0	0
Debt Service Coverage Ratio, Less Than One Point Zero X [Member] | Loan To Value Ratio Total [Member]
Financing Receivable	1,551	1,865
Debt Service Coverage Ratio Total [Member] | Loan To Value Ratio Less Than Fifty Nine Point Nine Nine Percent [Member]
Financing Receivable	271,881	260,793
Debt Service Coverage Ratio Total [Member] | Loan To Value Ratio Sixty Percent To Sixty Nine Point Nine Nine Percent [Member]
Financing Receivable	101,075	102,755
Debt Service Coverage Ratio Total [Member] | Loan-to-Value Ratio, Seventy Percent To Seventy Nine Point Nine Nine Percent [Member]
Financing Receivable	29,634	33,959
Debt Service Coverage Ratio Total [Member] | Loan-to-Value Ratio Greater than Eighty Percent [Member]
Financing Receivable	3,116	0
Debt Service Coverage Ratio Total [Member] | Loan To Value Ratio Total [Member]
Financing Receivable	$ 405,706	$ 397,507