Basis of Presentation and Significant Accounting Policies - Summary of Supplemental Cash Flow Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Supplemental Cash Flow Elements [Abstract]
Net cash paid for income taxes	$ 15,724	$ 5,787
Cash paid for interest expense	3,667	3,285
Acquisition of businesses
Cash paid for businesses purchased, excluding contingent consideration	16,836	21,242
Cash acquired in business acquisitions	(97)	(1,628)
Net cash paid for businesses purchased, net of cash acquired	16,739	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	2,758
Property and equipment received, but not paid	703	1,004
Total Non-cash investing and financing activities	$ 703	$ 3,762