CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended				6 Months Ended
		Jun. 28, 2019		Jun. 29, 2018		Jun. 28, 2019		Jun. 29, 2018
Income Statement [Abstract]
Revenue		$ 155,145		$ 150,400		$ 312,331		$ 297,365
Cost of revenue		89,363		85,171		180,260		169,977
Gross profit		65,782		65,229		132,071		127,388
Operating expenses:
Research and development and engineering		13,388		12,551		27,385		24,540
Selling, general and administrative		29,204		29,231		61,051		58,451
Amortization of purchased intangible assets		3,772		3,893		7,770		7,591
Restructuring and acquisition related costs		4,313		2,439		6,367		2,464
Total operating expenses		50,677		48,114		102,573		93,046
Operating income		15,105		17,115		29,498		34,342
Interest income (expense), net		(2,160)		(2,561)		(4,204)		(4,919)
Foreign exchange transaction gains (losses), net		27		177		68		(230)
Other income (expense), net		(70)		(46)		(138)		(87)
Income before income taxes		12,902		14,685		25,224		29,106
Income tax provision		2,522		3,060		2,591		4,644
Consolidated net income		10,380	[1]	11,625	[2]	22,633	[1]	24,462	[2]
Less: Net income attributable to noncontrolling interest	[2]			(625)				(1,551)
Net income attributable to Novanta Inc.		$ 10,380	[1]	$ 11,000	[2]	$ 22,633	[1]	$ 22,911	[2]
Earnings per common share attributable to Novanta Inc. (Note 5):
Basic		$ 0.30	[1]	$ 0.32	[2]	$ 0.65	[1]	$ 0.51	[2]
Diluted		$ 0.29	[1]	$ 0.32	[2]	$ 0.64	[1]	$ 0.50	[2]
Weighted average common shares outstanding—basic		34,998	[1]	34,949	[2]	34,981	[1]	34,919	[2]
Weighted average common shares outstanding—diluted		35,503	[1]	35,474	[2]	35,491	[1]	35,451	[2]

[1] 45,252 non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team and 213,219 shares of restricted stock issued to Laser Quantum former non-controlling interest holders are considered contingently issuable shares and are excluded from the calculation of the denominator as the contingent conditions had not been met as of June 28, 2019.

[2] 53,968 non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team were considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of June 29, 2018.