Reinsurance - Schedule of the Effect of Reinsurance on Premiums Written and Earned (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Premiums Written and Earned [Abstract]
Gross Written	$ 278,294	$ 303,090	$ 333,460
Ceded Written	(10,469)	(10,276)	(8,995)
Net premiums Written	267,825	292,814	324,465
Gross Earned	286,462	314,703	341,883
Ceded Earned	(10,469)	(10,276)	(8,995)
Net premiums Earned	$ 275,993	$ 304,427	$ 332,888