Acquisitions - Summary of Useful Lives of Customer Relationships Based on Customer Attrition (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($)
Acquired Finite Lived Intangible Assets [Line Items]
Estimated Useful life (years)	9 years 10 months 24 days
WAM Technologies, LLC [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Total intangible assets	$ 4,810
WAM Technologies, LLC [Member] | Customer Lists One Customer [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Estimated Useful life (years)	10 years
Total intangible assets	$ 3,720
WAM Technologies, LLC [Member] | Customer Lists All Other Customers [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Estimated Useful life (years)	11 years
Total intangible assets	$ 600
WAM Technologies, LLC [Member] | Technology [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Estimated Useful life (years)	10 years
Total intangible assets	$ 450
WAM Technologies, LLC [Member] | Trademarks [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Estimated Useful life (years)	1 year
Total intangible assets	$ 40