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Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net Investment Income [Line Items]
Net investment income earned	$ 55,967	$ 50,618
Fixed Income Securities [Member]
Net Investment Income [Line Items]
Net investment income earned	50,253	49,033
Commercial Mortgage Loans [Member]
Net Investment Income [Line Items]
Net investment income earned	62	0
Equity Securities [Member]
Net Investment Income [Line Items]
Net investment income earned	1,552	1,640
Short-Term Investments [Member]
Net Investment Income [Line Items]
Net investment income earned	1,166	2,044
Other Investments [Member]
Net Investment Income [Line Items]
Net investment income earned	6,342	660
Investment Expenses [Member]
Net Investment Income [Line Items]
Net investment income earned	$ (3,408)	$ (2,759)

X

- Definition

Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(2))
-URI http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263

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- Definition

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+ References

No definition available.

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