Business Combinations - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended				9 Months Ended
	Apr. 30, 2017	Dec. 31, 2016	Aug. 31, 2016	Jul. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Purchase price, net of cash acquired					$ 5,496	$ 20,911
Acquisition and integration costs					$ 900
Nutfield
Business Acquisition [Line Items]
Purchase price, net of cash acquired	$ 5,500
MWF
Business Acquisition [Line Items]
Purchase price, net of cash acquired		$ 6,600
LPT
Business Acquisition [Line Items]
Purchase price, net of cash acquired			$ 17,200
BuildIT
Business Acquisition [Line Items]
Purchase price, net of cash acquired				$ 3,900