Basis of Presentation and Significant Accounting Policies - Summary of Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Net cash paid for income taxes	$ 7,115	$ 4,203
Cash paid for interest expense	2,011	1,812
Acquisition of businesses
Cash paid for businesses purchased, excluding contingent consideration	13,512	21,242
Cash acquired in business acquisitions	0	(1,628)
Net cash paid for businesses purchased, net of cash acquired	13,512	19,614
Common stock issued in connection with Reggiani Macchine SpA ("Reggiani") acquisition	0	73
Non-cash investing and financing activities:
Non-cash settlement of vacation liabilities by issuing restricted stock units ("RSUs")	0	2,733
Property and equipment received, but not paid	843	880
Total Non-cash investing and financing activities	$ 843	$ 3,613