Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Net Investment Income [Line Items]
Gross investment income	$ 226,113	$ 175,485
Investment expense	(2,715)	(1,973)
Net investment income	223,398	173,512
Fixed maturity securities, including cash and cash equivalents and loans receivable
Net Investment Income [Line Items]
Gross investment income	195,642	101,284
Arbitrage trading account
Net Investment Income [Line Items]
Gross investment income	2,180	52,012
Equity securities
Net Investment Income [Line Items]
Gross investment income	13,746	10,856
Investment funds
Net Investment Income [Line Items]
Gross investment income	18,256	9,187
Real estate
Net Investment Income [Line Items]
Gross investment income	$ (3,711)	$ 2,146

Amount of expenses related to the generation of investment income.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.9)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-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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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))
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Investment Income (Loss), Interest And Dividend

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