Income Taxes	3 Months Ended
Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes For interim income tax reporting, the Company estimates its annual effective tax rate and applies it to year-to-date pretax income (loss), excluding unusual or infrequently occurring discrete items. Tax jurisdictions with losses for which tax benefits cannot be realized are excluded. The Company recorded income tax (benefit) provision of $(0.2) million and $1.0 million for the three months ended December 31, 2018 and 2017, respectively. In December 2017, the Tax Cuts and Jobs Act tax legislation was signed into law, which reduced the U.S. Federal statutory tax rate from 35% to 21%, among other changes. As a result of the enactment of this legislation, the tax provision for the first three months of fiscal 2018 included discrete tax expense of $1.2 million from the Company’s net deferred tax assets revaluation based on the enacted tax rate of 21%, as compared with the previous rate of 35%. The effective income tax rate for the three months ended December 31, 2018 differs from the U.S. federal statutory tax rate of 21% primarily due to the favorable impacts of stock award activity and increased U.S. federal research and development tax credits. These benefits were partly offset by non-deductible acquired intangible asset amortization, as well as operating losses incurred in Ireland, where tax benefits are offset by a valuation allowance. The effective income tax rate for the three months ended December 31, 2017 differs from the U.S. federal statutory tax rate of 24.5% primarily due to operating losses incurred in Ireland, where tax benefits are offset by a valuation allowance, and non-deductible acquired intangible asset amortization, contingent consideration accretion, including fair value adjustments, as well as unrealized foreign currency translation losses on Euro-denominated contingent consideration liabilities. These increases to the effective income tax rate were partially offset by the U.S. federal research and development income tax credit. The effective income tax rate for the three months ended December 31, 2018 and 2017 was impacted by discrete tax benefits of $0.5 million and $0.2 million, respectively, related to share awards vested, expired, cancelled and exercised during the periods. The total amount of unrecognized tax benefits, excluding interest and penalties that, if recognized, would affect the effective tax rate is $1.7 million and $1.4 million as of December 31, 2018 and September 30, 2018, respectively. Interest and penalties related to unrecognized tax benefits are recorded in the income tax (benefit) provision. The Company files income tax returns, including returns for its subsidiaries, in the U.S. federal jurisdiction and in various state jurisdictions as well as several non-U.S. jurisdictions. Uncertain tax positions are related to tax years that remain subject to examination. U.S. income tax returns for years prior to fiscal 2015 are no longer subject to examination by federal tax authorities. For tax returns for state and local jurisdictions, the Company is no longer subject to examination for tax years generally before fiscal 2007. For tax returns for non-U.S. jurisdictions, the Company is no longer subject to income tax examination for years prior to 2012. Additionally, the Company has been indemnified of liability for any taxes relating to Creagh Medical and NorMedix for periods prior to their respective acquisition dates, pursuant to the terms of the related share purchase agreements. As of December 31, 2018 and September 30, 2018, there were no undistributed earnings in foreign subsidiaries. The Internal Revenue Service (“IRS”) completed an examination of our fiscal 2016 U.S. federal income tax return in the third quarter of fiscal 2018, with a payment made associated primarily with timing adjustments.

Income Taxes

3 Months Ended

Dec. 31, 2018

13. Income Taxes

For interim income tax reporting, the Company estimates its annual effective tax rate and applies it to year-to-date pretax income (loss), excluding unusual or infrequently occurring discrete items. Tax jurisdictions with losses for which tax benefits cannot be realized are excluded. The Company recorded income tax (benefit) provision of $(0.2) million and $1.0 million for the three months ended December 31, 2018 and 2017, respectively. In December 2017, the Tax Cuts and Jobs Act tax legislation was signed into law, which reduced the U.S. Federal statutory tax rate from 35% to 21%, among other changes. As a result of the enactment of this legislation, the tax provision for the first three months of fiscal 2018 included discrete tax expense of $1.2 million from the Company’s net deferred tax assets revaluation based on the enacted tax rate of 21%, as compared with the previous rate of 35%.

The effective income tax rate for the three months ended December 31, 2018 differs from the U.S. federal statutory tax rate of 21% primarily due to the favorable impacts of stock award activity and increased U.S. federal research and development tax credits. These benefits were partly offset by non-deductible acquired intangible asset amortization, as well as operating losses incurred in Ireland, where tax benefits are offset by a valuation allowance. The effective income tax rate for the three months ended December 31, 2017 differs from the U.S. federal statutory tax rate of 24.5% primarily due to operating losses incurred in Ireland, where tax benefits are offset by a valuation allowance, and non-deductible acquired intangible asset amortization, contingent consideration accretion, including fair value adjustments, as well as unrealized foreign currency translation losses on Euro-denominated contingent consideration liabilities. These increases to the effective income tax rate were partially offset by the U.S. federal research and development income tax credit. The effective income tax rate for the three months ended December 31, 2018 and 2017 was impacted by discrete tax benefits of $0.5 million and $0.2 million, respectively, related to share awards vested, expired, cancelled and exercised during the periods.

The total amount of unrecognized tax benefits, excluding interest and penalties that, if recognized, would affect the effective tax rate is $1.7 million and $1.4 million as of December 31, 2018 and September 30, 2018, respectively. Interest and penalties related to unrecognized tax benefits are recorded in the income tax (benefit) provision.

The Company files income tax returns, including returns for its subsidiaries, in the U.S. federal jurisdiction and in various state jurisdictions as well as several non-U.S. jurisdictions. Uncertain tax positions are related to tax years that remain subject to examination. U.S. income tax returns for years prior to fiscal 2015 are no longer subject to examination by federal tax authorities. For tax returns for state and local jurisdictions, the Company is no longer subject to examination for tax years generally before fiscal 2007. For tax returns for non-U.S. jurisdictions, the Company is no longer subject to income tax examination for years prior to 2012. Additionally, the Company has been indemnified of liability for any taxes relating to Creagh Medical and NorMedix for periods prior to their respective acquisition dates, pursuant to the terms of the related share purchase agreements. As of December 31, 2018 and September 30, 2018, there were no undistributed earnings in foreign subsidiaries. The Internal Revenue Service (“IRS”) completed an examination of our fiscal 2016 U.S. federal income tax return in the third quarter of fiscal 2018, with a payment made associated primarily with timing adjustments.