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Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net Investment Income [Line Items]
Net investment income earned	$ 97,696	$ 70,222	$ 189,202	$ 142,824
Fixed Income Securities [Member]
Net Investment Income [Line Items]
Net investment income earned	83,916	62,144	164,003	116,069
Commercial Mortgage Loans [Member]
Net Investment Income [Line Items]
Net investment income earned	2,199	1,192	4,164	2,162
Equity Securities [Member]
Net Investment Income [Line Items]
Net investment income earned	2,236	2,639	3,441	5,057
Short-Term Investments [Member]
Net Investment Income [Line Items]
Net investment income earned	2,892	407	7,542	508
Alternative Investments [Member]
Net Investment Income [Line Items]
Net investment income earned	11,396	9,274	19,164	28,402
Other Investments [Member]
Net Investment Income [Line Items]
Net investment income earned	188	(214)	231	(37)
Investment expenses [Member]
Net Investment Income [Line Items]
Net investment income earned	$ (5,131)	$ (5,220)	$ (9,343)	$ (9,337)

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 https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

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+ References

No definition available.

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