Investments - Securities with Gross Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2021 USD ($) security
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	$ (455)
Less Than Twelve Months, Fair Value	41,250
Total, Gross Unrealized Loss	(455)
Total, Fair Value	$ 41,250
Number of securities in an unrealized loss position | security	358
Unrealized loss position for 12 months or longer | security	0
U.S. Treasuries
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	$ (36)
Less Than Twelve Months, Fair Value	5,007
Total, Gross Unrealized Loss	(36)
Total, Fair Value	5,007
Obligations of states, municipalities and political subdivisions
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(84)
Less Than Twelve Months, Fair Value	4,292
Total, Gross Unrealized Loss	(84)
Total, Fair Value	4,292
Industrial and miscellaneous
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(155)
Less Than Twelve Months, Fair Value	15,446
Total, Gross Unrealized Loss	(155)
Total, Fair Value	15,446
Residential and commercial mortgage-backed securities
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(139)
Less Than Twelve Months, Fair Value	9,687
Total, Gross Unrealized Loss	(139)
Total, Fair Value	9,687
Other loan-backed and structured securities
Net Investment Income [Line Items]
Less Than Twelve Months, Gross Unrealized Loss	(41)
Less Than Twelve Months, Fair Value	6,818
Total, Gross Unrealized Loss	(41)
Total, Fair Value	$ 6,818