Summary of Fair Values of Assets Acquired and Liabilities Assumed Purchase Price Allocation (Details) $ in Thousands, € in Millions, £ in Millions					12 Months Ended
	Jul. 03, 2017 USD ($)	Jan. 10, 2017 USD ($)	Jan. 10, 2017 GBP (£)	May 24, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jul. 03, 2017 EUR (€)	Jan. 10, 2017 GBP (£)
Business Acquisition [Line Items]
Goodwill					$ 210,988	$ 108,128	$ 103,456
Less: contingent consideration					1,304	2,381
Net cash used for acquisition of businesses					$ 168,332	$ 8,958	25,987
World of Medicine GmbH
Business Acquisition [Line Items]
Cash	$ 1,400
Accounts receivable	11,807
Inventories	14,549
Property, plant and equipment	21,940
Intangible assets	59,732
Goodwill	55,632
Other assets	2,660
Total assets acquired	167,720
Accounts payable	4,398
Other liabilities	8,681
Deferred tax liabilities	19,707
Total liabilities assumed	32,786
Total assets acquired, net of liabilities assumed	134,934							€ 118.1
Less: cash acquired	1,400
Total purchase price, net of cash acquired	$ 133,534
Laser Quantum
Business Acquisition [Line Items]
Cash		$ 15,343
Accounts receivable		2,739
Inventories		6,264
Property, plant and equipment		2,286
Intangible assets		38,955
Goodwill		31,168
Other assets		717
Total assets acquired		97,472
Accounts payable		796
Other liabilities		2,068
Deferred tax liabilities		7,337
Total liabilities assumed		10,201
Total assets acquired, net of liabilities assumed		87,271
Less: fair value of equity interest previously held by Novanta		34,637
Less: fair value of noncontrolling interest		21,582							£ 17.7
Total purchase price paid by Novanta		31,052	£ 25.5
Less: cash acquired		15,343
Total purchase price, net of cash acquired		15,709
Thing Magic
Business Acquisition [Line Items]
Inventories		1,832
Intangible assets		7,423
Goodwill		9,929
Total assets acquired		19,184
Other liabilities		95
Total liabilities assumed		95
Total assets acquired, net of liabilities assumed		$ 19,089
Reach Technology Inc.
Business Acquisition [Line Items]
Cash				$ 238
Accounts receivable				991
Inventories				1,611
Prepaid expenses and other current assets				12
Intangible assets				3,953
Goodwill				4,715
Total assets acquired				11,520
Accounts payable				280
Other liabilities				148
Deferred tax liabilities				1,474
Total liabilities assumed				1,902
Total assets acquired, net of liabilities assumed				9,618
Less: cash acquired				238
Total purchase price, net of cash acquired				$ 9,380
Skyetek, Lincoln Laser and Applimotion
Business Acquisition [Line Items]
Cash							331
Accounts receivable							3,166
Inventories							3,544
Prepaid expenses and other current assets							148
Property, plant and equipment							3,220
Intangible assets							11,370
Goodwill							12,668
Other assets							10
Total assets acquired							34,457
Accounts payable							1,681
Other liabilities							1,197
Deferred tax liabilities							2,308
Total liabilities assumed							5,186
Total assets acquired, net of liabilities assumed							29,271
Less: cash acquired							331
Total purchase price, net of cash acquired							28,940
Less: contingent consideration							3,459
Net cash used for acquisition of businesses							$ 25,481