Deferred Policy Acquisition Costs - Schedule of Major Categories of the Deferred Policy Acquisition Costs (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Charges Insurers [Abstract]
Agents’ commissions	$ 14,953	$ 15,238
Premium taxes	3,161	3,395
Deferred underwriting expenses	1,620	1,618
Total deferred policy acquisition costs	$ 19,734	$ 20,251	$ 19,300	$ 20,412

Net amount of deferred policy acquisition costs capitalized on contracts remaining in force as of the balance sheet date.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant