Goodwill and Other Intangible Assets - Summary of Changes in Gross Carrying Amounts of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill Roll Forward
Goodwill, Beginning Balance	$ 12,025	$ 5,231
Goodwill acquired		6,794
Goodwill adjustment	80
Goodwill, Ending Balance	$ 12,105	$ 12,025