Income Taxes - Summary of Components of Net Deferred Tax Asset (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Deferred tax assets, gross	$ 6,934	$ 5,988
Valuation allowance	(3,900)	(3,898)
Deferred tax assets, net	3,034	2,090
Deferred tax liabilities:
Deferred tax liabilities, gross	(3,034)	(2,090)
Federal [Member]
Deferred tax assets:
Deferred tax assets, gross	6,059	5,311
Deferred tax liabilities:
Deferred tax liabilities, gross	(2,461)	(1,720)
State [Member]
Deferred tax assets:
Deferred tax assets, gross	875	677
Deferred tax liabilities:
Deferred tax liabilities, gross	$ (573)	$ (370)