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Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement [Line Items]
Net investment income earned	$ 326,589	$ 227,107	$ 222,543
Fixed Income Securities [Member]
Statement [Line Items]
Net investment income earned	209,709	203,926	203,255
Commercial Mortgage Loans [Member]
Statement [Line Items]
Net investment income earned	2,743	844	0
Equity Securities [Member]
Statement [Line Items]
Net investment income earned	15,920	9,286	6,996
Short-term Investments [Member]
Statement [Line Items]
Net investment income earned	260	1,821	6,653
Other Investment Portfolio [Member]
Statement [Line Items]
Net investment income earned	118,060	26,922	18,778
Investment Expenses [Member]
Statement [Line Items]
Net investment income earned	$ (20,103)	$ (15,692)	$ (13,139)

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=120400993&loc=SL114874131-224263

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+ References

No definition available.

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