Investments (Fixed Maturities Securities Proceeds) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Debt Securities, Available-for-sale [Line Items]
Proceeds from maturities/prepayments			$ 2,290,052	$ 1,096,571
Fixed maturities | Available-for-sale
Debt Securities, Available-for-sale [Line Items]
Proceeds from sales	$ 248,635	$ 151,383	676,660	280,064
Proceeds from maturities/prepayments	483,079	318,188	1,618,992	806,521
Gross investment gains from sales and maturities	2,921	1,377	13,265	10,826
Gross investment losses from sales and maturities	(9,153)	(10,920)	(33,625)	(28,445)
Write-downs recognized in earnings	(9,534)	4	(9,534)	11
(Addition to) release of allowance for credit losses	$ (11,227)	$ 608	(12,567)	454
Noncash or part noncash divestiture, amount of consideration received			$ (5,600)	$ 10,000