Investments (Commercial Mortgage and Other Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 1,231,761	$ 1,241,653
Commercial mortgage loans, Percentage	100.00%	100.00%
Allowance for Credit Losses	$ (4,641)	$ (1,768)
Total net other loans	0	0
Other loans	0	0
Allowance for credit losses, other loans	0	0
Total net commercial mortgage and other loans	1,227,120	1,239,885
Commercial Mortgage and Agricultural Loans
Commercial Mortgage and Other Loans [Line Items]
Total net other loans	1,227,120	1,239,885
Other collateralized loans
Commercial Mortgage and Other Loans [Line Items]
Other loans	0	0
Apartments and multi-family
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 374,770	$ 355,175
Commercial mortgage loans, Percentage	30.40%	28.60%
Hospitality
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 33,919	$ 31,449
Commercial mortgage loans, Percentage	2.80%	2.50%
Industrial
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 323,057	$ 299,803
Commercial mortgage loans, Percentage	26.20%	24.10%
Office
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 191,822	$ 205,498
Commercial mortgage loans, Percentage	15.60%	16.60%
Other
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 137,809	$ 136,841
Commercial mortgage loans, Percentage	11.20%	11.00%
Retail
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 150,449	$ 190,690
Commercial mortgage loans, Percentage	12.20%	15.40%
Commercial mortgage loans
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 1,211,826	$ 1,219,456
Commercial mortgage loans, Percentage	98.40%	98.20%
Agricultural property loans
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 19,935	$ 22,197
Commercial mortgage loans, Percentage	1.60%	1.80%

Commercial mortgage loans, Percentage

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Commercial mortgage and agricultural property loans by property type

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Commercial mortgage and other loans

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Other loans

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- Definition

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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