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