Investments (Fixed Maturities Securities Proceeds) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Proceeds from maturities/prepayments	$ 1,418,413	$ 534,863
Fixed maturities \| Available-for-sale
Debt Securities, Available-for-sale [Line Items]
Proceeds from sales	422,037	106,155
Proceeds from maturities/prepayments	845,709	437,443
Gross investment gains from sales and maturities	4,608	937
Gross investment losses from sales and maturities	(7,802)	(8,132)
Write-downs recognized in earnings	(6,336)	0
(Addition to) release of allowance for credit losses	(2,414)	358
Noncash or part noncash divestiture, amount of consideration received	$ 150,700	$ (8,700)

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