Summary of Significant Accounting Policies - Summary of Reconciliation of Contingent Consideration (Detail) - JBBR Acquisition [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule Of Reconciliation Of Contingent Consideration [Line Items]
Beginning balance			$ 18,000
Revaluation Adjustments	$ 500	$ 500	1,465	$ (300)
Earn-out payments	(600)	$ (300)	(1,865)	$ (1,000)
Ending balance	$ 17,600		$ 17,600