Reconciliation of Statutory Canadian Tax rate to Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Effective Tax Rate Reconciliation [Line Items]
Statutory Canadian tax rate	21.00%	35.00%
Income Tax Provision (benefit)	$ 10,207	$ 13,827	$ 10,519
Canada Revenue Agency
Schedule Of Effective Tax Rate Reconciliation [Line Items]
Statutory Canadian tax rate	29.00%	29.00%	28.50%
Expected income tax provision at Canadian statutory tax rate	$ 17,778	$ 22,079	$ 9,269
International tax rate differences	(4,474)	(2,038)	891
U.S. state income taxes, net	831	674	503
Withholding and other taxes	550	484	441
Permanent differences and other	1,015	1,582	84
Section 199 deduction		(1,148)	(1,063)
Foreign-derived intangible income	(1,628)
Tax credits	(1,250)	(984)	(1,095)
Statutory tax rate changes	(285)	2,823	(856)
Uncertain tax positions	190	(1,607)	(103)
Change in valuation allowance	(262)	(354)	1,202
Acquisition contingent consideration adjustments	833	149	762
Transaction costs	172	1,011	649
Provision to return differences	(385)	225	(93)
Benefit from share-based compensation	(931)	(837)	(72)
Gain on Laser Quantum acquisition		(6,586)
UK patent box	(1,947)	(1,646)
Income Tax Provision (benefit)	$ 10,207	$ 13,827	$ 10,519
Effective tax rate	16.70%	18.20%	32.30%