Income Taxes	6 Months Ended
Jun. 29, 2018
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes The Company determines its estimated annual effective tax rate at the end of each interim period based on full-year forecasted pre-tax income and facts known at that time. The estimated annual effective tax rate is applied to the year-to-date pre-tax income at the end of each interim period with the cumulative effect of any changes in the estimated annual effective tax rate being recorded in the fiscal quarter in which the change is determined. The tax effect of significant unusual items is reflected in the period in which they occur. Since the Company is incorporated in Canada, it is required to use Canada’s statutory tax rate of 29.0% in the determination of the estimated annual effective tax rate. The Company’s effective tax rate of 20.8% for the three months ended June 29, 2018 differs from the Canadian statutory tax rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, including the benefit of the new 21% U.S. corporate income tax rate, estimated deductions for Foreign Derived Intangible Income under the Tax Reform Act, and U.K. patent box deductions and other tax credits; offset by non-deductible expenses recognized under an earn-out agreement in connection with the Zettlex acquisition. The Company’s effective tax rate of 16.0% for the six months ended June 29, 2018 differs from the Canadian statutory tax rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, including the benefit of the new 21% U.S. corporate income tax rate, estimated deductions for Foreign Derived Intangible Income under the Tax Reform Act, U.K. patent box deductions and other tax credits, and windfall tax benefits upon vesting of certain equity awards during the period; offset by non-deductible expenses recognized under an earn-out agreement in connection with the Zettlex acquisition. The Company’s effective tax rate of 31.9% for the three months ended June 30, 2017 differs from the Canadian statutory rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, losses in jurisdictions with a full valuation allowance, and other discrete items for the period. The Company’s effective tax rate of 11.6% for the six months ended June 30, 2017 differs from the Canadian statutory tax rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, losses in jurisdictions with a full valuation allowance, the impact associated with establishing control over Laser Quantum upon the acquisition of an additional approximately 35% of Laser Quantum’s outstanding shares, and other discrete items for the period. The Company reported a nontaxable gain of $26.4 million on its previously-held Laser Quantum equity interest and wrote off $1.4 million of Laser Quantum related deferred tax liability, which had a combined 18.9% favorable impact on the effective tax rate for the six months ended June 30, 2017. The Company maintains a valuation allowance on some of its deferred tax assets in certain jurisdictions. A valuation allowance is required when, based upon an assessment of various factors, including recent operating loss history, anticipated future earnings, and prudent and reasonable tax planning strategies, it is more likely than not that some portion of the deferred tax assets will not be realized. On December 22, 2017, the President of the United States signed into law the Tax Reform Act. The Tax Reform Act significantly changes U.S. tax law by, among other things, lowering the U.S. corporate income tax rate from 35% to 21% effective January 1, 2018, implementing a territorial tax system, providing a one-time transition toll charge (“Toll Charge”) on accumulated foreign earnings, creating a new limitation on deductible interest expense and modifying the limitation on officer compensation. As a result of the Tax Reform Act, the Company was required to revalue certain deferred tax assets and liabilities at the newly enacted 21% U.S. federal corporate income tax rate. This revaluation resulted in an additional income tax provision of $2.8 million for the year ended December 31, 2017 and a corresponding reduction in the net deferred tax assets and liabilities. Because of the ownership structure of the Company, the Company’s foreign entities outside the U.S. are not considered controlled foreign corporations of the U.S. company, as defined under U.S. tax principles, and accordingly, the accumulated earnings of these foreign subsidiaries are not subject to the one-time Toll Charge under the Tax Reform Act. ASC 740, “Income Taxes,” requires a company to record the effects of a tax law change in the period of enactment. ASU 2018-05 allows a company to record a provisional amount when it does not have the necessary information available, prepared, or analyzed in reasonable detail to complete its accounting for the changes in the Tax Reform Act. The measurement period ends when the company has obtained, prepared and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year from the date of enactment of the Tax Reform Act. The Company currently anticipates finalizing and recording any resulting adjustments by December 2018. During the six months ended June 29, 2018, there were no changes made to the provisional amounts recognized in 2017 in connection with the enactment of the Tax Reform Act. The Company will continue to analyze the effects of the Tax Reform Act. Additional impacts from the Tax Reform Act will be recorded as they are identified during the measurement period as provided for in ASU 2018-05. The final impact of the Tax Reform Act may differ from the provisional amounts that have been recognized, possibly materially, due to, among other things, changes in the Company’s interpretation of the Tax Reform Act, legislative or administrative actions to clarify the intent of the statutory language that differ from the Company’s current interpretation, any changes in accounting standards for income taxes or related interpretations in response to the Tax Reform Act, or any updates or changes to estimates utilized to calculate the impacts, including changes to current year earnings estimates and applicable foreign exchange rates. Additionally, the Company’s U.S. tax returns for 2017 will be filed during or before the fourth quarter of 2018, and any changes to the tax positions for temporary differences compared to the estimates used for the provisional amounts will result in an adjustment to the estimated tax benefit recorded as of December 31, 2017. During the three and six months ended June 29, 2018, the Company recorded estimates for certain deductions now available in 2018 under the Tax Reform Act. These estimates may be subject to revision as future guidance or clarification is received from the U.S. taxing authorities.

12. Income Taxes

The Company determines its estimated annual effective tax rate at the end of each interim period based on full-year forecasted pre-tax income and facts known at that time. The estimated annual effective tax rate is applied to the year-to-date pre-tax income at the end of each interim period with the cumulative effect of any changes in the estimated annual effective tax rate being recorded in the fiscal quarter in which the change is determined. The tax effect of significant unusual items is reflected in the period in which they occur. Since the Company is incorporated in Canada, it is required to use Canada’s statutory tax rate of 29.0% in the determination of the estimated annual effective tax rate.

The Company’s effective tax rate of 20.8% for the three months ended June 29, 2018 differs from the Canadian statutory tax rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, including the benefit of the new 21% U.S. corporate income tax rate, estimated deductions for Foreign Derived Intangible Income under the Tax Reform Act, and U.K. patent box deductions and other tax credits; offset by non-deductible expenses recognized under an earn-out agreement in connection with the Zettlex acquisition.

The Company’s effective tax rate of 16.0% for the six months ended June 29, 2018 differs from the Canadian statutory tax rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, including the benefit of the new 21% U.S. corporate income tax rate, estimated deductions for Foreign Derived Intangible Income under the Tax Reform Act, U.K. patent box deductions and other tax credits, and windfall tax benefits upon vesting of certain equity awards during the period; offset by non-deductible expenses recognized under an earn-out agreement in connection with the Zettlex acquisition.

The Company’s effective tax rate of 31.9% for the three months ended June 30, 2017 differs from the Canadian statutory rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, losses in jurisdictions with a full valuation allowance, and other discrete items for the period.

The Company’s effective tax rate of 11.6% for the six months ended June 30, 2017 differs from the Canadian statutory tax rate of 29.0% primarily due to the mix of income earned in jurisdictions with varying tax rates, losses in jurisdictions with a full valuation allowance, the impact associated with establishing control over Laser Quantum upon the acquisition of an additional approximately 35% of Laser Quantum’s outstanding shares, and other discrete items for the period. The Company reported a nontaxable gain of $26.4 million on its previously-held Laser Quantum equity interest and wrote off $1.4 million of Laser Quantum related deferred tax liability, which had a combined 18.9% favorable impact on the effective tax rate for the six months ended June 30, 2017.

The Company maintains a valuation allowance on some of its deferred tax assets in certain jurisdictions. A valuation allowance is required when, based upon an assessment of various factors, including recent operating loss history, anticipated future earnings, and prudent and reasonable tax planning strategies, it is more likely than not that some portion of the deferred tax assets will not be realized.

On December 22, 2017, the President of the United States signed into law the Tax Reform Act. The Tax Reform Act significantly changes U.S. tax law by, among other things, lowering the U.S. corporate income tax rate from 35% to 21% effective January 1, 2018, implementing a territorial tax system, providing a one-time transition toll charge (“Toll Charge”) on accumulated foreign earnings, creating a new limitation on deductible interest expense and modifying the limitation on officer compensation.

As a result of the Tax Reform Act, the Company was required to revalue certain deferred tax assets and liabilities at the newly enacted 21% U.S. federal corporate income tax rate. This revaluation resulted in an additional income tax provision of $2.8 million for the year ended December 31, 2017 and a corresponding reduction in the net deferred tax assets and liabilities. Because of the ownership structure of the Company, the Company’s foreign entities outside the U.S. are not considered controlled foreign corporations of the U.S. company, as defined under U.S. tax principles, and accordingly, the accumulated earnings of these foreign subsidiaries are not subject to the one-time Toll Charge under the Tax Reform Act.

ASC 740, “Income Taxes,” requires a company to record the effects of a tax law change in the period of enactment. ASU 2018-05 allows a company to record a provisional amount when it does not have the necessary information available, prepared, or analyzed in reasonable detail to complete its accounting for the changes in the Tax Reform Act. The measurement period ends when the company has obtained, prepared and analyzed the information necessary to finalize its accounting, but cannot extend beyond one year from the date of enactment of the Tax Reform Act. The Company currently anticipates finalizing and recording any resulting adjustments by December 2018.

During the six months ended June 29, 2018, there were no changes made to the provisional amounts recognized in 2017 in connection with the enactment of the Tax Reform Act. The Company will continue to analyze the effects of the Tax Reform Act. Additional impacts from the Tax Reform Act will be recorded as they are identified during the measurement period as provided for in ASU 2018-05. The final impact of the Tax Reform Act may differ from the provisional amounts that have been recognized, possibly materially, due to, among other things, changes in the Company’s interpretation of the Tax Reform Act, legislative or administrative actions to clarify the intent of the statutory language that differ from the Company’s current interpretation, any changes in accounting standards for income taxes or related interpretations in response to the Tax Reform Act, or any updates or changes to estimates utilized to calculate the impacts, including changes to current year earnings estimates and applicable foreign exchange rates. Additionally, the Company’s U.S. tax returns for 2017 will be filed during or before the fourth quarter of 2018, and any changes to the tax positions for temporary differences compared to the estimates used for the provisional amounts will result in an adjustment to the estimated tax benefit recorded as of December 31, 2017. During the three and six months ended June 29, 2018, the Company recorded estimates for certain deductions now available in 2018 under the Tax Reform Act. These estimates may be subject to revision as future guidance or clarification is received from the U.S. taxing authorities.