Income Taxes	3 Months Ended
Mar. 31, 2018
Income Taxes [Abstract]
Income Taxes	7. Income Taxes Income Tax Expense Our effective income tax rate was a benefit of 44% and 27% for the three months ended March 31, 2018 and 2017, respectively. Our income tax rate for the three months ended March 31, 2018 was favorably impacted by losses in high rate jurisdictions and excess tax benefit deductions related to stock compensation, partially offset by unfavorable impacts of non-deductible operating expenses and executive compensation expenses. Our income tax rate for the three months ended March 31, 2017 was favorably affected by excess tax benefits, primarily related to the exercise of non-qualified stock options and the vesting of stock awards, which decreased income tax expense by approximately $1.1 million. On December 22, 2017 the U.S. enacted tax reform legislation known as the H.R. 1, commonly referred to as the “Tax Cuts and Jobs Act” (the “Tax Act”), resulting in significant modifications to existing law. We have elected to follow the guidance in SEC Staff Accounting Bulletin 118 (“SAB 118”), which provides additional clarification regarding the application of ASC Topic 740 in situations where we do not have the necessary information available, prepared, or analyzed in reasonable detail to complete the accounting for certain income tax effects of the Tax Act for the reporting period in which the Tax Act was enacted. SAB 118 provides for a measurement period beginning in the reporting period that includes the Tax Act’s enactment date and ending when we have obtained, prepared, and analyzed the information needed in order to complete the accounting requirements but the measurement period cannot extend beyond one year from the enactment date. As of March 31, 2018 we have not completed our accounting for the income tax effects of all elements of the Tax Act. Where we could make reasonable estimates of the effects of elements for which our analysis is not yet complete, we recorded provisional adjustments. If we were not yet able to make reasonable estimates of the impact of certain elements, we have not recorded any adjustments related to those elements and have continued accounting for them in accordance with ASC Topic 740 based on the tax laws in effect before the Tax Act. We recorded a one-time estimated deemed repatriation transition tax resulting in a nominal tax benefit to us based on the interplay of the transition tax and the foreign tax credit in 2017. The provisional amount is based on information currently available including information from our recent acquisition of JOTEC. We continue to gather and analyze information, including historical adjustments to earnings and profits of foreign subsidiaries, in order to complete the accounting for the effects of the estimated transition tax. For our calendar year beginning in 2018, we are subject to several provisions of the Tax Act including computations under Global Intangible Low Taxed Income (“GILTI”), Foreign Derived Intangible Income (“FDII”), Base Erosion and Anti-Abuse Tax (“BEAT”), and Internal Revenue Code Section 163(j) interest limitation (“Interest Limitation”) rules. Based on preliminary information and analysis, we have not recorded a provisional estimate in our effective tax rate for the three months ended March 31, 2018 for these provisions because we currently estimate that these provisions of the Tax Act will not impact our 2018 effective rate. We will continue to refine our provisional estimates for our computations of the GILTI, FDII, BEAT, and Interest Limitation rules as we gather additional information. As we complete our analysis of the Tax Act, further collect and analyze data, interpret any additional guidance issued by the U.S. Treasury Department, the Internal Revenue Service, and other standard-setting bodies, we may adjust our provisional amounts. Those adjustments may materially impact our provision for income taxes in the period in which the adjustments are made. Deferred Income Taxes We generate deferred tax assets primarily as a result of write-downs of inventory and deferred preservation costs; accruals for product and tissue processing liability claims; investment and asset impairments and due to operating losses. We acquired significant deferred tax assets, primarily net operating loss carryforwards, from our acquisitions of JOTEC in 2017, On-X in 2016, Hemosphere, Inc. in 2012, and Cardiogenesis Corporation in 2011. We recorded significant deferred tax liabilities in 2017 related to the intangible assets acquired in the JOTEC Acquisition. As of March 31, 2018 we maintained a total of $2.5 million in valuation allowances against deferred tax assets, related to state net operating loss carryforwards, and had a net deferred tax liability of $28.5 million. As of December 31, 2017 we had a total of $2.5 million in valuation allowances against deferred tax assets, related to state net operating loss carryforwards, and a net deferred tax liability of $28.8 million.

7. Income Taxes

Income Tax Expense

Our effective income tax rate was a benefit of 44% and 27% for the three months ended March 31, 2018 and 2017, respectively. Our income tax rate for the three months ended March 31, 2018 was favorably impacted by losses in high rate jurisdictions and excess tax benefit deductions related to stock compensation, partially offset by unfavorable impacts of non-deductible operating expenses and executive compensation expenses.

Our income tax rate for the three months ended March 31, 2017 was favorably affected by excess tax benefits, primarily related to the exercise of non-qualified stock options and the vesting of stock awards, which decreased income tax expense by approximately $1.1 million.

On December 22, 2017 the U.S. enacted tax reform legislation known as the H.R. 1, commonly referred to as the “Tax Cuts and Jobs Act” (the “Tax Act”), resulting in significant modifications to existing law. We have elected to follow the guidance in SEC Staff Accounting Bulletin 118 (“SAB 118”), which provides additional clarification regarding the application of ASC Topic 740 in situations where we do not have the necessary information available, prepared, or analyzed in reasonable detail to complete the accounting for certain income tax effects of the Tax Act for the reporting period in which the Tax Act was enacted. SAB 118 provides for a measurement period beginning in the reporting period that includes the Tax Act’s enactment date and ending when we have obtained, prepared, and analyzed the information needed in order to complete the accounting requirements but the measurement period cannot extend beyond one year from the enactment date.

As of March 31, 2018 we have not completed our accounting for the income tax effects of all elements of the Tax Act. Where we could make reasonable estimates of the effects of elements for which our analysis is not yet complete, we recorded provisional adjustments. If we were not yet able to make reasonable estimates of the impact of certain elements, we have not recorded any adjustments related to those elements and have continued accounting for them in accordance with ASC Topic 740 based on the tax laws in effect before the Tax Act.

We recorded a one-time estimated deemed repatriation transition tax resulting in a nominal tax benefit to us based on the interplay of the transition tax and the foreign tax credit in 2017. The provisional amount is based on information currently available including information from our recent acquisition of JOTEC. We continue to gather and analyze information, including historical adjustments to earnings and profits of foreign subsidiaries, in order to complete the accounting for the effects of the estimated transition tax.

For our calendar year beginning in 2018, we are subject to several provisions of the Tax Act including computations under Global Intangible Low Taxed Income (“GILTI”), Foreign Derived Intangible Income (“FDII”), Base Erosion and Anti-Abuse Tax (“BEAT”), and Internal Revenue Code Section 163(j) interest limitation (“Interest Limitation”) rules. Based on preliminary information and analysis, we have not recorded a provisional estimate in our effective tax rate for the three months ended March 31, 2018 for these provisions because we currently estimate that these provisions of the Tax Act will not impact our 2018 effective rate. We will continue to refine our provisional estimates for our computations of the GILTI, FDII, BEAT, and Interest Limitation rules as we gather additional information.

As we complete our analysis of the Tax Act, further collect and analyze data, interpret any additional guidance issued by the U.S. Treasury Department, the Internal Revenue Service, and other standard-setting bodies, we may adjust our provisional amounts. Those adjustments may materially impact our provision for income taxes in the period in which the adjustments are made.

Deferred Income Taxes

We generate deferred tax assets primarily as a result of write-downs of inventory and deferred preservation costs; accruals for product and tissue processing liability claims; investment and asset impairments and due to operating losses. We acquired significant deferred tax assets, primarily net operating loss carryforwards, from our acquisitions of JOTEC in 2017, On-X in 2016, Hemosphere, Inc. in 2012, and Cardiogenesis Corporation in 2011. We recorded significant deferred tax liabilities in 2017 related to the intangible assets acquired in the JOTEC Acquisition.

As of March 31, 2018 we maintained a total of $2.5 million in valuation allowances against deferred tax assets, related to state net operating loss carryforwards, and had a net deferred tax liability of $28.5 million. As of December 31, 2017 we had a total of $2.5 million in valuation allowances against deferred tax assets, related to state net operating loss carryforwards, and a net deferred tax liability of $28.8 million.