Investments (Fixed Maturities Securities Proceeds) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt Securities, Available-for-sale [Line Items]
Proceeds from maturities/prepayments			$ 1,096,571	$ 1,511,002
Fixed maturities | Available-for-sale
Debt Securities, Available-for-sale [Line Items]
Proceeds from sales	$ 151,383	$ 377,344	280,064	1,055,433
Proceeds from maturities/prepayments	318,188	222,454	806,521	453,241
Gross investment gains from sales and maturities	1,377	(2,527)	10,826	(3,885)
Gross investment losses from sales and maturities	(10,920)	(2,371)	(28,445)	(44,274)
Write-downs recognized in earnings	4	(1,088)	11	(20,604)
(Addition to) release of allowance for credit losses	$ 608	$ 98	454	(563)
Noncash or part noncash divestiture, amount of consideration received			$ 10,000	$ 2,300