Redeemable Noncontrolling Interest- Schedule of Reconciliation of Changes in Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 29, 2017	Sep. 29, 2017
Noncontrolling Interest [Abstract]
Acquisition of noncontrolling interest		$ 21,582
Net income attributable to noncontrolling interest	$ 834	1,444
Adjustment of redeemable noncontrolling interest to estimated redemption value	7,585	11,303	[1]
Foreign currency translation		2,509
Balance as of September 29, 2017	$ 36,838	$ 36,838

[1] Adjustment of the carrying value of redeemable noncontrolling interest to the estimated redemption value was recognized in retained earnings instead of the consolidated statement of operations but was included in the computation of earnings per share attributable to Novanta Inc. (see Note 5.)