CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands		3 Months Ended
		Mar. 30, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Consolidated net income		$ 12,837	$ 34,274
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	[1]	3,671	1,440
Pension liability adjustments, net of tax	[2]	(116)	205
Total other comprehensive income		3,555	1,645
Total consolidated comprehensive income		16,392	35,919
Less: Comprehensive income attributable to noncontrolling interest		(926)	(22)
Comprehensive income attributable to Novanta Inc.		$ 15,466	$ 35,897

[1] The tax effect on this component of comprehensive income was nominal for all periods presented.

[2] The tax effect on this component of comprehensive income was nominal for all periods presented. See Note 3 for the total amount of pension liability adjustments reclassified out of accumulated other comprehensive income (loss).