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
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 412,167	$ 205,293	$ 778,555	$ 394,963
Less: investment expenses	(19,092)	(13,165)	(36,030)	(23,535)
Net investment income	393,075	192,128	742,525	371,428
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	2,543	1,190	5,320	1,352
Commercial mortgage and other loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	56,317	22,801	104,973	45,049
Policy loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	10,622	5,153	15,618	10,219
Other invested assets
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	15,624	38,243	41,723	75,033
Short-term investments and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	29,582	3,441	60,758	4,089
Available-for-sale \| Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	275,718	121,986	510,528	231,177
Trading \| Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 21,761	$ 12,479	$ 39,635	$ 28,044

Amount, before 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.

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Amount of expenses related to the generation of investment income.

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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.

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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.

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