CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenue	$ 614,337	$ 521,290	$ 384,758
Cost of revenue	352,809	300,759	222,306
Gross profit	261,528	220,531	162,452
Operating expenses:
Research and development and engineering	51,024	41,673	32,002
Selling, general and administrative	115,900	101,654	81,299
Amortization of purchased intangible assets	15,550	12,096	8,251
Restructuring, acquisition and divestiture related costs	8,041	7,542	7,945
Total operating expenses	190,515	162,965	129,497
Operating income	71,013	57,566	32,955
Interest income (expense), net	(9,814)	(7,165)	(4,559)
Foreign exchange transaction gains (losses), net	147	(447)	2,317
Other income (expense), net	(44)	(229)	1,809
Gain on acquisition of business		26,409
Income before income taxes	61,302	76,134	32,522
Income tax provision	10,207	13,827	10,519
Consolidated net income	51,095	62,307	22,003
Less: Net income attributable to noncontrolling interest	(1,986)	(2,256)
Net income attributable to Novanta Inc.	$ 49,109	$ 60,051	$ 22,003
Earnings per common share attributable to Novanta Inc. (Note 10):
Basic	$ 1.46	$ 1.14	$ 0.63
Diluted	$ 1.43	$ 1.13	$ 0.63
Weighted average common shares outstanding—basic	34,913	34,817	34,694
Weighted average common shares outstanding—diluted	35,473	35,280	34,914