Investments (Analysis of Past Due Commercial Mortgage, Agricultural and Other Loans) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Current	$ 138,371	$ 143,263
Total Loans	138,371	143,263
Non-Accrual Status	0	0
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Commercial Mortgage Loans
Financing Receivable, Past Due [Line Items]
Current	135,899	139,803
Total Loans	135,899	139,803
Non-Accrual Status	0	0
Commercial Mortgage Loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Commercial Mortgage Loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Commercial Mortgage Loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Agricultural property loans
Financing Receivable, Past Due [Line Items]
Current	2,472	3,460
Total Loans	2,472	3,460
Non-Accrual Status	0	0
Agricultural property loans | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Agricultural property loans | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Agricultural property loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Past Due	0	0
Loans | 90 Days or More Past Due
Financing Receivable, Past Due [Line Items]
Accruing Interest	$ 0	$ 0