Debt (Details) - USD ($) $ in Thousands			3 Months Ended	12 Months Ended
	Nov. 10, 2023	Sep. 15, 2023	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Nov. 10, 2021
Debt Instrument [Line Items]
Debt				$ 100,000	$ 199,863
Interest paid				$ 9,000	$ 8,000	$ 7,000
Average interest rate on debt (as a percent)				4.07%	3.89%	4.77%
Weighted average interest rate on debt (as a percent)				6.26%
FHLBC
Debt Instrument [Line Items]
Debt instrument maturity date	Nov. 12, 2024
Amount borrowed from FHLB	$ 50,000			$ 50,000
Repayments of FHLB advances	$ 50,000
Interest paid monthly at an annualized rate							0.84%
Average interest rate on debt (as a percent)	5.44%
FHLBC | RLI Ins.
Debt Instrument [Line Items]
Frequency of interest payment				monthly
Senior Notes Maturing September 15, 2023
Debt Instrument [Line Items]
Retirement of senior notes		$ 150,000
Stated interest rate, payable semi-annually (as a percent)		4.875%
Line of Credit | PNC
Debt Instrument [Line Items]
Proceeds from line of credit		$ 50,000
Floating interest rate		7.07%
Maximum borrowing capacity - Line of credit			$ 100,000
Maximum borrowing capacity conditional expansion			$ 130,000
Term of facility			3 years
Line of credit facility expiration date			May 29, 2026
Line of Credit | Bank of Montreal, Chicago Branch
Debt Instrument [Line Items]
Maximum borrowing capacity - Line of credit					$ 60,000
Line of credit facility expiration date					Mar. 27, 2023