Income Taxes - Tax Effect of Each Type of Temporary Difference and Carry Forward that Gives Rise to Deferred Tax Asset (Detail) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Allowance for doubtful accounts	$ 59	$ 36
Accrued compensation	692	489
Total book to tax difference in partnership	(404)	(356)
Net operating loss	79	130
Valuation allowance	0	(299)
Net deferred tax asset	$ 426	$ 0