CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenue	$ 521,290	$ 384,758	$ 373,598
Cost of revenue	300,759	222,306	215,708
Gross profit	220,531	162,452	157,890
Operating expenses:
Research and development and engineering	41,673	32,002	31,043
Selling, general and administrative	102,025	81,691	82,049
Amortization of purchased intangible assets	12,096	8,251	7,611
Restructuring, acquisition and divestiture related costs	7,542	7,945	8,254
Total operating expenses	163,336	129,889	128,957
Operating income from continuing operations	57,195	32,563	28,933
Interest income (expense), net	(7,165)	(4,559)	(5,180)
Foreign exchange transaction gains (losses), net	(447)	2,317	(23)
Other income (expense), net	142	2,201	2,663
Gain on acquisition of business	26,409
Gain on disposal of business			19,629
Income from continuing operations before income taxes	76,134	32,522	46,022
Income tax provision	13,827	10,519	10,394
Income from continuing operations	62,307	22,003	35,628
Loss from discontinued operations, net of tax			(13)
Consolidated net income	62,307	22,003	35,615
Less: Net income attributable to noncontrolling interest	(2,256)
Net income attributable to Novanta Inc.	$ 60,051	$ 22,003	$ 35,615
Earnings per common share from continuing operations (Note 9):
Basic	$ 1.14	$ 0.63	$ 1.03
Diluted	1.13	0.63	1.02
Loss per common share from discontinued operations (Note 9):
Basic			0.00
Diluted			0.00
Earnings per common share attributable to Novanta Inc. (Note 9):
Basic	1.14	0.63	1.03
Diluted	$ 1.13	$ 0.63	$ 1.02
Weighted average common shares outstanding—basic	34,817	34,694	34,579
Weighted average common shares outstanding—diluted	35,280	34,914	34,827
Amounts attributable to Novanta Inc.:
Income from continuing operations	$ 60,051	$ 22,003	$ 35,628
Loss from discontinued operations			(13)
Net income attributable to Novanta Inc.	$ 60,051	$ 22,003	$ 35,615