Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Operating Loss Carryforwards	$ 17,000,000
Unrecognized Tax Benefits	$ 0
Federal statutory rate	21.00%	35.00%	35.00%
Annual effective income tax rate, percentage	19.00%	47.00%	30.00%
Net deferred tax asset	$ 23,566,000	$ 25,509,000
Alternative minimum tax credit carryforward	216,000	201,000
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	$ (346,000)	$ (16,709,000)	$ 0