Investments (Aggregated Income Statement Summarized Financial Information for Partnerhips in our Alternative Investment Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Schedule of Equity Method Investments [Line Items]
Net investment income earned	$ 97,696	$ 70,222	$ 189,202	$ 142,824
Investments accounted for under the equity method [Member]
Schedule of Equity Method Investments [Line Items]
Net investment income (loss)	(70,600)	270,900	(141,300)	406,500
Realized gains	922,000	6,233,500	2,644,300	8,981,500
Net change in unrealized appreciation (depreciation)	3,754,000	(3,962,400)	5,197,800	1,215,900
Net income	4,605,400	2,542,000	7,700,800	10,603,900
Alternative Investments [Member]
Schedule of Equity Method Investments [Line Items]
Net investment income earned	$ 11,396	$ 9,274	$ 19,164	$ 28,402

The amount of net income (loss) reported by an equity method investment of the entity.

No definition available.

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- Definition

This item represents the disclosure of summarized financial information, specifically the aggregate change in unrealized appreciation (depreciation), for unconsolidated subsidiaries and 50 percent-or-less owned entities accounted for under the equity method of accounting.

+ References

No definition available.

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- Definition

This item represents the disclosure of summarized financial information, specifically aggregate net investment income, for unconsolidated subsidiaries and 50 percent-or-less owned entities accounted for under the equity method accounting.

+ References

No definition available.

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This item represents the disclosure of summarized financial information, specifically aggregate realized gains (losses), for unconsolidated subsidiaries and 50 percent-or-less owned entities accounted for under the equity method of accounting.

+ References

No definition available.

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- 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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- 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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