Goodwill and Intangible Assets - Amortization Expense on Existing Intangible Assets for Next Four Years (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Finite Lived Intangible Assets Future Amortization Expense [Abstract]
Remainder of 2017	$ 219
2018	268
2019	242
2020	179
Total	$ 908	$ 969