CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Income Statement [Abstract]
Revenue		$ 590,623		$ 626,099		$ 614,337
Cost of revenue		346,106		364,014		352,809
Gross profit		244,517		262,085		261,528
Operating expenses:
Research and development and engineering		60,996		55,965		51,024
Selling, general and administrative		109,853		118,407		115,900
Amortization of purchased intangible assets		13,970		15,857		15,550
Restructuring and acquisition related costs		3,810		16,574		8,041
Total operating expenses		188,629		206,803		190,515
Operating income		55,888		55,282		71,013
Interest income (expense), net		(6,564)		(8,493)		(9,814)
Foreign exchange transaction gains (losses), net		(942)		(780)		147
Other income (expense), net		21		(243)		(44)
Income before income taxes		48,403		45,766		61,302
Income tax provision		3,882		4,993		10,207
Consolidated net income		44,521	[1]	40,773	[2]	51,095	[3]
Less: Net income attributable to noncontrolling interest	[3]					(1,986)
Net income attributable to Novanta Inc.		$ 44,521	[1]	$ 40,773	[2]	$ 49,109	[3]
Earnings per common share attributable to Novanta Inc. (Note 9):
Basic		$ 1.27	[1]	$ 1.16	[2]	$ 1.46	[3]
Diluted		$ 1.25	[1]	$ 1.15	[2]	$ 1.43	[3]
Weighted average common shares outstanding—basic		35,144	[1]	35,030	[2]	34,913	[3]
Weighted average common shares outstanding—diluted		35,654	[1]	35,546	[2]	35,473	[3]

[1] For the year ended December 31, 2020, 45 non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team and 213 shares of restricted stock issued to Laser Quantum former non-controlling interest shareholders are considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of December 31, 2020.

[2] For the year ended December 31, 2019, 46 non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team and 213 shares of restricted stock issued to Laser Quantum former non-controlling interest shareholders were considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of December 31, 2019.

[3] For the year ended December 31, 2018, 54 non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team and 213 shares of restricted stock issued to Laser Quantum former non-controlling interest shareholders were considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of December 31, 2018.