CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016
Statement Of Income And Comprehensive Income [Abstract]
Consolidated net income		$ 9,990	$ 4,871	$ 44,264	$ 6,777
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	[1]	3,589	(2,915)	5,029	(2,850)
Pension liability adjustments, net of tax	[2]	(117)	846	88	1,295
Total other comprehensive income (loss)		3,472	(2,069)	5,117	(1,555)
Total consolidated comprehensive income (loss)		13,462	2,802	49,381	5,222
Less: Comprehensive income attributable to noncontrolling interest		(588)		(610)
Comprehensive income (loss) attributable to Novanta Inc.		$ 12,874	$ 2,802	$ 48,771	$ 5,222

[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 4 for the total amount of pension liability adjustments reclassified out of accumulated other comprehensive income (loss).