Investments - Securities with Gross Unrealized Loss Position (Details) $ in Thousands	Mar. 31, 2022 USD ($) item security	Dec. 31, 2021 USD ($) item security
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	$ (2,807)	$ (455)
Less Than Twelve Months, Fair Value	55,520	41,250
Total, Gross Unrealized Loss	(2,807)	(455)
Total, Fair Value	$ 55,520	$ 41,250
Number of securities in an unrealized loss position | security	448	358
Unrealized loss position for 12 months or longer | item	0	0
U.S. Treasuries
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	$ (135)	$ (36)
Less Than Twelve Months, Fair Value	3,204	5,007
Total, Gross Unrealized Loss	(135)	(36)
Total, Fair Value	3,204	5,007
Obligations of states, municipalities and political subdivisions
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(584)	(84)
Less Than Twelve Months, Fair Value	9,361	4,292
Total, Gross Unrealized Loss	(584)	(84)
Total, Fair Value	9,361	4,292
Corporate Bonds
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(1,234)	(155)
Less Than Twelve Months, Fair Value	21,104	15,446
Total, Gross Unrealized Loss	(1,234)	(155)
Total, Fair Value	21,104	15,446
Residential and commercial mortgage-backed securities
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(617)	(139)
Less Than Twelve Months, Fair Value	13,816	9,687
Total, Gross Unrealized Loss	(617)	(139)
Total, Fair Value	13,816	9,687
Other loan-backed and structured securities
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(237)	(41)
Less Than Twelve Months, Fair Value	8,035	6,818
Total, Gross Unrealized Loss	(237)	(41)
Total, Fair Value	$ 8,035	$ 6,818