Fair Value Measurements - Company's Fair Value Hierarchy for its Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financial liabilities:
Total financial liabilities	$ 8,089	$ 10,540
Zero2Ten and Branchbird Contingent Earnout Consideration [Member]
Financial liabilities:
Total financial liabilities	8,089	10,540
Significant Unobservable Inputs (Level 3) [Member]
Financial liabilities:
Total financial liabilities	8,089	10,540
Significant Unobservable Inputs (Level 3) [Member] | Zero2Ten and Branchbird Contingent Earnout Consideration [Member]
Financial liabilities:
Total financial liabilities	$ 8,089	$ 10,540