Acquisitions - Additional Information (Detail) $ in Millions	1 Months Ended	6 Months Ended
	Feb. 29, 2016 USD ($) PowerCenter	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)
Business Acquisition [Line Items]
Revenues from the date of acquisition		$ 2.2	$ 2.1
Power Center Acquired [Member]
Business Acquisition [Line Items]
Business acquisitions value	$ 60.5
Number of business acquired | PowerCenter	1
Consideration paid in cash	$ 59.9