Business Combinations - Schedule of Purchase Price Allocation to the Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	1 Months Ended					12 Months Ended
	Apr. 30, 2017	Dec. 31, 2016	Aug. 31, 2016	Jul. 31, 2016	Mar. 31, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 46,744				$ 67,274	$ 52,750	$ 46,744
Total purchase price, net of cash acquired						$ 27,067	$ 5,596	27,708
Nutfield (Final)
Business Acquisition [Line Items]
Accounts receivable					$ 160
Inventory					539
Other assets					96
Deferred income tax assets					131
Intangible assets					2,329
Goodwill					2,357
Accounts payable and accrued liabilities					(12)
Other liabilities (2)					(104)
Deferred income tax liabilities					0
Total purchase price, net of cash acquired	$ 5,500				$ 5,496
Laser Controls Systems (Final)
Business Acquisition [Line Items]
Accounts receivable				$ 0
Inventory				0
Other assets				0
Deferred income tax assets				0
Intangible assets				1,400
Goodwill				928
Accounts payable and accrued liabilities				0
Other liabilities (2)				(579)
Deferred income tax liabilities				0
Total purchase price, net of cash acquired				$ 1,749
Photocore AG (Final)
Business Acquisition [Line Items]
Accounts receivable			$ 0
Inventory			0
Other assets			0
Deferred income tax assets			0
Intangible assets			1,435
Goodwill			1,010
Accounts payable and accrued liabilities			0
Other liabilities (2)			0
Deferred income tax liabilities			0
Total purchase price, net of cash acquired			$ 2,445
Lanmark (Final)
Business Acquisition [Line Items]
Accounts receivable		610						610
Inventory		299						299
Other assets		76						76
Deferred income tax assets		0						0
Intangible assets		1,366						1,366
Goodwill		5,355						5,355
Accounts payable and accrued liabilities		(159)						(159)
Other liabilities (2)		(971)						(971)
Deferred income tax liabilities		(325)						$ (325)
Total purchase price, net of cash acquired		$ 6,251
Open Technologies
Business Acquisition [Line Items]
Accounts receivable	2,735
Inventory	1,852
Other assets	634
Deferred income tax assets	0
Intangible assets	10,388
Goodwill	9,130
Accounts payable and accrued liabilities	(2,926)
Other liabilities (2)	(5,201)
Deferred income tax liabilities	0
Total purchase price, net of cash acquired	$ 16,612