Investments (Commercial Mortgage and Other Loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 1,801,799	$ 1,773,152
Commercial mortgage loans, Percentage	100.00%	100.00%
Allowance for credit losses	$ (7,001)	$ (7,382)
Total net commercial mortgage and agricultural property loans	1,794,798	1,765,770
Apartments and multi-family
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 363,747	$ 369,764
Commercial mortgage loans, Percentage	20.20%	20.90%
Hospitality
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 18,064	$ 16,679
Commercial mortgage loans, Percentage	1.00%	0.90%
Industrial
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 607,002	$ 590,231
Commercial mortgage loans, Percentage	33.70%	33.30%
Office
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 362,173	$ 374,107
Commercial mortgage loans, Percentage	20.10%	21.10%
Other
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 224,733	$ 187,643
Commercial mortgage loans, Percentage	12.50%	10.60%
Retail
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 129,817	$ 130,154
Commercial mortgage loans, Percentage	7.20%	7.30%
Commercial Mortgage Loans
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 1,705,536	$ 1,668,578
Commercial mortgage loans, Percentage	94.70%	94.10%
Agricultural property loans
Commercial Mortgage and Other Loans [Line Items]
Commercial mortgage and agricultural property loans	$ 96,263	$ 104,574
Commercial mortgage loans, Percentage	5.30%	5.90%

Commercial mortgage loans, Percentage

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- Definition

Commercial mortgage and agricultural property loans by property type

+ References

No definition available.

+ Details

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121581245&loc=d3e21338-158488

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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