CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Consolidated net income		$ 40,773	[1]	$ 51,095	[2]	$ 62,307	[3]
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	[4]	3,267		(4,172)		8,909
Pension liability adjustments, net of tax	[5]	1,147		(475)		926
Total other comprehensive income (loss)		4,414		(4,647)		9,835
Total consolidated comprehensive income		45,187		46,448		72,142
Less: Comprehensive income attributable to noncontrolling interest				(1,986)		(2,256)
Comprehensive income attributable to Novanta Inc.		$ 45,187		$ 44,462		$ 69,886

[1] 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 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, 2019.

[2] 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.

[3] For the year ended December 31, 2017, 59 non-GAAP EPS performance-based restricted stock units granted to certain members of the executive management team were excluded from the calculation of the denominator as the contingent conditions had not been met as of December 31, 2017.

[4] The tax effect on this component of comprehensive income was $3, ($93) and ($94) in 2019, 2018 and 2017, respectively.

[5] The tax effect on this component of comprehensive income was $267, ($153) and $277 in 2019, 2018 and 2017, respectively.