Income Taxes	6 Months Ended
Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our income tax provision was $35.5 million and $64.7 million in the three and six months ended June 30, 2017, respectively, compared to $42.1 million and $74.5 million for the same periods in 2016. The effective tax rates were 25.1% and 25.2% in the three and six months ended June 30, 2017, respectively, compared to 26.9% and 28.1% for the same periods in 2016. The decrease in the effective tax rate for the three months ended June 30, 2017 compared to the same period in 2016 was primarily due to changes in income mix among the various jurisdictions in which we operate. The decrease in the effective tax rate for the six months ended June 30, 2017 compared to the same period in 2016 was primarily due to changes in income mix among the various jurisdictions in which we operate and tax benefit associated with share-based compensation. The effective tax rates for the three and six months ended June 30, 2017 were higher than the Irish statutory rate of 12.5% primarily due to income taxable at a rate higher than the Irish statutory rate, uncertain tax positions, and various expenses not deductible for tax purposes, partially offset by originating tax credits and deductions available in relation to subsidiary equity. We do not provide for Irish income taxes on undistributed earnings of our foreign operations that are intended to be indefinitely reinvested in our foreign subsidiaries. Our net deferred tax liability primarily arose due to the Celator Acquisition. The balance is net of deferred tax assets which are comprised primarily of U.S. federal and state net operating loss carryforwards, foreign net operating loss carryforwards and other temporary differences. We maintain a valuation allowance against certain foreign and U.S. federal and state deferred tax assets. Each reporting period, we evaluate the need for a valuation allowance on our deferred tax assets by jurisdiction and adjust our estimates as more information becomes available. We are required to recognize the financial statement effects of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. As a result, we have established a liability for certain tax benefits which we judge may not be sustained upon examination. Our most significant tax jurisdictions are Ireland, the U.S. (both at the federal level and in various state jurisdictions), Italy and France. Because of our net operating loss carryforwards and tax credit carryforwards, substantially all of our tax years remain open to federal, state, and foreign tax examination. Certain of our subsidiaries are currently under examination by the French tax authorities for the years ended December 31, 2012 through 2016. These examinations may lead to ordinary course adjustments or proposed adjustments to our taxes. In December 2015, we received proposed tax assessment notices from the French tax authorities for 2012 and 2013 relating to certain transfer pricing adjustments. The notices propose additional French tax of approximately $43.7 million, including interest and penalties through the date of the assessment, translated at the foreign exchange rate at June 30, 2017. We disagree with the proposed assessment and intend to contest it vigorously.

Income Taxes

Our income tax provision was $35.5 million and $64.7 million in the three and six months ended June 30, 2017, respectively, compared to $42.1 million and $74.5 million for the same periods in 2016. The effective tax rates were 25.1% and 25.2% in the three and six months ended June 30, 2017, respectively, compared to 26.9% and 28.1% for the same periods in 2016. The decrease in the effective tax rate for the three months ended June 30, 2017 compared to the same period in 2016 was primarily due to changes in income mix among the various jurisdictions in which we operate. The decrease in the effective tax rate for the six months ended June 30, 2017 compared to the same period in 2016 was primarily due to changes in income mix among the various jurisdictions in which we operate and tax benefit associated with share-based compensation. The effective tax rates for the three and six months ended June 30, 2017 were higher than the Irish statutory rate of 12.5% primarily due to income taxable at a rate higher than the Irish statutory rate, uncertain tax positions, and various expenses not deductible for tax purposes, partially offset by originating tax credits and deductions available in relation to subsidiary equity. We do not provide for Irish income taxes on undistributed earnings of our foreign operations that are intended to be indefinitely reinvested in our foreign subsidiaries.

Our net deferred tax liability primarily arose due to the Celator Acquisition. The balance is net of deferred tax assets which are comprised primarily of U.S. federal and state net operating loss carryforwards, foreign net operating loss carryforwards and other temporary differences. We maintain a valuation allowance against certain foreign and U.S. federal and state deferred tax assets. Each reporting period, we evaluate the need for a valuation allowance on our deferred tax assets by jurisdiction and adjust our estimates as more information becomes available.

We are required to recognize the financial statement effects of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. As a result, we have established a liability for certain tax benefits which we judge may not be sustained upon examination. Our most significant tax jurisdictions are Ireland, the U.S. (both at the federal level and in various state jurisdictions), Italy and France. Because of our net operating loss carryforwards and tax credit carryforwards, substantially all of our tax years remain open to federal, state, and foreign tax examination. Certain of our subsidiaries are currently under examination by the French tax authorities for the years ended December 31, 2012 through 2016. These examinations may lead to ordinary course adjustments or proposed adjustments to our taxes. In December 2015, we received proposed tax assessment notices from the French tax authorities for 2012 and 2013 relating to certain transfer pricing adjustments. The notices propose additional French tax of approximately $43.7 million, including interest and penalties through the date of the assessment, translated at the foreign exchange rate at June 30, 2017. We disagree with the proposed assessment and intend to contest it vigorously.