Investments (Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	$ 21,410	$ 6,446	$ 20,263	$ 5,951
Addition to (release of) allowance for expected losses	683	3,478	1,830	3,973
Total ending balance	22,093	9,924	22,093	9,924
Commercial mortgage loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	20,427	6,324	19,665	5,847
Addition to (release of) allowance for expected losses	706	3,380	1,468	3,857
Total ending balance	21,133	9,704	21,133	9,704
Agricultural Property Loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of year	983	122	598	104
Addition to (release of) allowance for expected losses	(23)	98	362	116
Total ending balance	$ 960	$ 220	$ 960	$ 220