Income Taxes	3 Months Ended
Mar. 30, 2019
Income Taxes
Income Taxes	12. Income Taxes Provision (benefit) for income taxes includes both domestic and foreign income taxes at the applicable tax rates adjusted for non-deductible expenses, research and development tax credits and other permanent differences. Income tax expense (benefit) was $(2.5) million and $(4.4) million for the three months ended March 30, 2019 and March 31, 2018, resulting in effective tax rates of (85.0)% and (19.8)%, respectively. The effective tax rate for the three months ended March 30, 2019 decreased from the prior period primarily due to a change in the proportion of excess tax benefits from stock-based compensation relative to pre-tax book income. The tax benefit in both periods is the result of the windfall benefit on share-based instruments and the Federal research and development tax credit exceeding the Company’s tax provision. On July 27, 2015, the U.S. Tax Court issued an opinion in Altera Corp. v. Commissioner which concluded that related parties in an intercompany cost-sharing arrangement are not required to share costs related to stock-based compensation. In February 2016, the U.S. Internal Revenue Service appealed the decision to the U.S Court of Appeals for the Ninth Circuit (the “Ninth Circuit”). The Ninth Circuit reversed the 2015 decision of the U.S. Tax Court on July 24, 2018 but on August 7, 2018, withdrew its decision to allow time for a reconstituted panel to confer on the appeal. On October 16, 2018, a rehearing was held; however the Ninth Circuit has not yet issued its final decision. Although the U.S. Treasury has not withdrawn the requirement to include stock-based compensation from its regulations, based on the facts and circumstances of the Tax Court Case, the Company continues to reflect a tax benefit in its financial statements based on the expectation that the Tax Court decision will be upheld on appeal. The Company will continue to monitor ongoing developments and potential impacts to its financial statements. Uncertain Tax Positions As of March 30, 2019, the Company had gross unrecognized tax benefits, inclusive of interest, of $2.1 million which $2.1 million would affect the effective tax rate if recognized. During the three months ended March 30, 2019, the Company released $0.3 million of unrecognized tax benefits. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes. These amounts were not material for any of the periods presented. The Norwegian Tax Administration (“NTA”) has completed its examination of the Company’s Norwegian subsidiary for income tax matters relating to fiscal years 2013, 2014, 2015 and 2016. The Company received a final assessment from the NTA in December 2017 concerning an adjustment to its 2013 taxable income related to the pricing of an intercompany transaction. The Company is currently appealing the assessment. The revised adjustment to the pricing of the intercompany transaction results in approximately $16.4 million additional Norwegian income tax. The Company disagrees with the NTA’s assessment and believes the Company’s position on this matter is more likely than not to be sustained. The Company plans to exhaust all available administrative remedies, and if unable to resolve this matter through administrative remedies with the NTA, the Company plans to pursue judicial remedies. The Company believes that it has accrued adequate reserves related to all matters contained in tax periods open to examination. Should the Company experience an unfavorable outcome in the NTA matter, however, such an outcome could have a material impact on its financial statements. Tax years 2015 through 2019 remain open to examination by the major taxing jurisdictions in which the Company operates. The Company is not currently under audit in any major taxing jurisdiction.

12. Income Taxes

Provision (benefit) for income taxes includes both domestic and foreign income taxes at the applicable tax rates adjusted for non-deductible expenses, research and development tax credits and other permanent differences. Income tax expense (benefit) was $(2.5) million and $(4.4) million for the three months ended March 30, 2019 and March 31, 2018, resulting in effective tax rates of (85.0)% and (19.8)%, respectively. The effective tax rate for the three months ended March 30, 2019 decreased from the prior period primarily due to a change in the proportion of excess tax benefits from stock-based compensation relative to pre-tax book income. The tax benefit in both periods is the result of the windfall benefit on share-based instruments and the Federal research and development tax credit exceeding the Company’s tax provision.

On July 27, 2015, the U.S. Tax Court issued an opinion in Altera Corp. v. Commissioner which concluded that related parties in an intercompany cost-sharing arrangement are not required to share costs related to stock-based compensation. In February 2016, the U.S. Internal Revenue Service appealed the decision to the U.S Court of Appeals for the Ninth Circuit (the “Ninth Circuit”). The Ninth Circuit reversed the 2015 decision of the U.S. Tax Court on July 24, 2018 but on August 7, 2018, withdrew its decision to allow time for a reconstituted panel to confer on the appeal. On October 16, 2018, a rehearing was held; however the Ninth Circuit has not yet issued its final decision. Although the U.S. Treasury has not withdrawn the requirement to include stock-based compensation from its regulations, based on the facts and circumstances of the Tax Court Case, the Company continues to reflect a tax benefit in its financial statements based on the expectation that the Tax Court decision will be upheld on appeal. The Company will continue to monitor ongoing developments and potential impacts to its financial statements.

Uncertain Tax Positions

As of March 30, 2019, the Company had gross unrecognized tax benefits, inclusive of interest, of $2.1 million which $2.1 million would affect the effective tax rate if recognized. During the three months ended March 30, 2019, the Company released $0.3 million of unrecognized tax benefits.

The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes. These amounts were not material for any of the periods presented.

The Norwegian Tax Administration (“NTA”) has completed its examination of the Company’s Norwegian subsidiary for income tax matters relating to fiscal years 2013, 2014, 2015 and 2016. The Company received a final assessment from the NTA in December 2017 concerning an adjustment to its 2013 taxable income related to the pricing of an intercompany transaction. The Company is currently appealing the assessment. The revised adjustment to the pricing of the intercompany transaction results in approximately $16.4 million additional Norwegian income tax. The Company disagrees with the NTA’s assessment and believes the Company’s position on this matter is more likely than not to be sustained. The Company plans to exhaust all available administrative remedies, and if unable to resolve this matter through administrative remedies with the NTA, the Company plans to pursue judicial remedies.

The Company believes that it has accrued adequate reserves related to all matters contained in tax periods open to examination. Should the Company experience an unfavorable outcome in the NTA matter, however, such an outcome could have a material impact on its financial statements.

Tax years 2015 through 2019 remain open to examination by the major taxing jurisdictions in which the Company operates. The Company is not currently under audit in any major taxing jurisdiction.