Other Assets - Components of Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Other Assets [Abstract]
Prepaid reinsurance premiums	$ 153,072	$ 201,674
Loaned securities and securities sold under repurchase agreements (Note 5)	137,282	103,996
Company-owned life insurance	104,712	113,386
Right-of-use assets	30,653	31,878
Other	32,573	32,246
Total other assets	$ 458,292	$ 483,180