Investments - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	$ 597	$ 249
Provision and recoveries	164	201
Sales/collections and write-offs	(186)	(102)
Allowance for credit losses, end of period	575	348
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	0	0
Provision and recoveries	2,167	0
Sales/collections and write-offs	0	0
Allowance for credit losses, end of period	2,167	0
Other loans receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	11,081	3,775
Provision and recoveries	172	32
Sales/collections and write-offs	0	(98)
Allowance for credit losses, end of period	11,253	3,709
Agent loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit losses, beginning of period	957	957
Provision and recoveries	0	0
Sales/collections and write-offs	0	0
Allowance for credit losses, end of period	$ 957	$ 957