CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 27, 2019		Sep. 28, 2018		Sep. 27, 2019		Sep. 28, 2018
Income Statement [Abstract]
Revenue		$ 154,066		$ 160,794		$ 466,397		$ 458,159
Cost of revenue		90,012		91,160		270,272		261,137
Gross profit		64,054		69,634		196,125		197,022
Operating expenses:
Research and development and engineering		13,811		13,204		41,196		37,744
Selling, general and administrative		27,926		29,147		88,977		87,598
Amortization of purchased intangible assets		3,970		3,947		11,740		11,538
Restructuring and acquisition related costs		5,546		2,341		11,913		4,805
Total operating expenses		51,253		48,639		153,826		141,685
Operating income		12,801		20,995		42,299		55,337
Interest income (expense), net		(2,153)		(2,396)		(6,357)		(7,315)
Foreign exchange transaction gains (losses), net		387		66		455		(164)
Other income (expense), net		(48)		(44)		(186)		(131)
Income before income taxes		10,987		18,621		36,211		47,727
Income tax provision		2,064		3,632		4,655		8,276
Consolidated net income		8,923	[1]	14,989	[2]	31,556	[1]	39,451	[2]
Less: Net income attributable to noncontrolling interest	[2]			(435)				(1,986)
Net income attributable to Novanta Inc.		$ 8,923	[1]	$ 14,554	[2]	$ 31,556	[1]	$ 37,465	[2]
Earnings per common share attributable to Novanta Inc. (Note 5):
Basic		$ 0.25	[1]	$ 0.61	[2]	$ 0.90	[1]	$ 1.12	[2]
Diluted		$ 0.25	[1]	$ 0.60	[2]	$ 0.89	[1]	$ 1.11	[2]
Weighted average common shares outstanding—basic		35,074	[1]	34,899	[2]	35,012	[1]	34,918	[2]
Weighted average common shares outstanding—diluted		35,585	[1]	35,485	[2]	35,523	[1]	35,469	[2]

[1] 47,147 performance-based restricted stock units granted to certain members of the executive management team and 213,219 shares of restricted stock issued to Laser Quantum former non-controlling interest holders are considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of September 27, 2019.

[2] 53,968 performance-based restricted stock units granted to certain members of the executive management team and 213,219 shares of restricted stock issued to Laser Quantum former non-controlling interest holders were considered contingently issuable shares and were excluded from the calculation of the denominator as the contingent conditions had not been met as of September 28, 2018.