Income Taxes	6 Months Ended
Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	11. 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. 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 on income from continuing operations of 31.9% for the three 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, and other discrete items for the period. The Company’s effective tax rate on income from continuing operations 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’s effective tax rate on income from continuing operations of 33.9% for the three months ended July 1, 2016 differed from the Canadian statutory rate of 28.5% primarily due to the mix of income earned in jurisdictions with varying tax rates and losses in jurisdictions with a full valuation allowance. The Company’s effective tax rate on income from continuing operations of 29.4% for the six months ended July 1, 2016 differed from the Canadian statutory rate of 28.5% primarily due to the mix of income earned in jurisdictions with varying tax rates, losses in jurisdictions with a full valuation allowance, the Laser Quantum dividend distribution and the impact of other discrete items for the period. The Company received a tax free cash dividend of $2.3 million from Laser Quantum, which had a 4.4% favorable impact on the effective tax rate for the six months ended July 1, 2016. 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.

11. 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. 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 on income from continuing operations of 31.9% for the three 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, and other discrete items for the period.

The Company’s effective tax rate on income from continuing operations 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’s effective tax rate on income from continuing operations of 33.9% for the three months ended July 1, 2016 differed from the Canadian statutory rate of 28.5% primarily due to the mix of income earned in jurisdictions with varying tax rates and losses in jurisdictions with a full valuation allowance.

The Company’s effective tax rate on income from continuing operations of 29.4% for the six months ended July 1, 2016 differed from the Canadian statutory rate of 28.5% primarily due to the mix of income earned in jurisdictions with varying tax rates, losses in jurisdictions with a full valuation allowance, the Laser Quantum dividend distribution and the impact of other discrete items for the period. The Company received a tax free cash dividend of $2.3 million from Laser Quantum, which had a 4.4% favorable impact on the effective tax rate for the six months ended July 1, 2016.

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.