Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 2,527,151	$ 1,752,819	$ 939,282
Less: investment expenses	(105,134)	(77,297)	(55,281)
Net investment income	2,422,017	1,675,522	884,001
Equity securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	30,698	14,772	8,226
Commercial mortgage and other loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	328,853	231,994	119,358
Policy loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	65,825	48,118	21,189
Other invested assets
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	140,376	98,369	101,289
Short-term investments and cash equivalents
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	182,094	123,857	44,182
Available-for-sale | Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	1,622,898	1,139,581	589,248
Trading | Fixed maturities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 156,407	$ 96,128	$ 55,790