Investments (Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	$ 39,784	$ 42,682	$ 37,715	$ 37,689
Addition to (release of) allowance for expected losses	3,828	(1,110)	5,897	3,883
Write-downs charged against allowance	(5,096)	0	(5,096)	0
Total ending balance	38,516	41,572	38,516	41,572
Commercial mortgage loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	34,770	41,769	33,004	36,758
Addition to (release of) allowance for expected losses	1,046	(1,077)	2,812	3,934
Write-downs charged against allowance	0	0	0	0
Total ending balance	35,816	40,692	35,816	40,692
Agricultural Property Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	5,014	913	4,711	931
Addition to (release of) allowance for expected losses	2,782	(33)	3,085	(51)
Write-downs charged against allowance	(5,096)	0	(5,096)	0
Total ending balance	$ 2,700	$ 880	$ 2,700	$ 880