Deferred Policy Acquisition Costs - Schedule of Major Categories of the Deferred Policy Acquisition Costs (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Charges Insurers [Abstract]
Agents’ commissions	$ 14,290	$ 14,953
Premium taxes	2,960	3,161
Deferred underwriting expenses	1,798	1,620
Total deferred policy acquisition costs	$ 19,048	$ 19,734	$ 20,251	$ 19,300