Income taxes	9 Months Ended
Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income taxes	Income taxes The effective tax rates for the three and nine months ended September 30, 2017, were 15.1% and 15.4%, respectively, compared with 16.6% and 15.9%, respectively, for the corresponding periods of the prior year. The effective rates differ from the federal statutory rates primarily as a result of indefinitely invested earnings of our foreign operations. We do not provide for U.S. income taxes on undistributed earnings of our foreign operations that are intended to be invested indefinitely outside the United States. The decrease in our effective tax rate for the three months ended September 30, 2017, was due primarily to favorable tax impacts of changes in the jurisdictional mix of income and expenses, as well as discrete benefits associated with the impairment of our AMG 899 (formerly TA-8995) asset and the related release of contingent consideration liabilities connected with the acquisition of Dezima Pharma B.V. (Dezima) (see Note 8, Goodwill and other intangible assets and Note 11, Fair value measurement), offset partially by adjustments to certain federal tax credits and deductions. The decrease in our effective tax rate for the nine months ended September 30, 2017, was due primarily to favorable tax impacts of changes in the jurisdictional mix of income and expenses, as well as discrete benefits associated with the effective settlement of certain state and federal tax matters, offset partially by lower tax benefits from share-based compensation payments and adjustments to certain federal tax credits and deductions. The U.S. territory of Puerto Rico imposes an excise tax on the gross intercompany purchase price of goods and services from our manufacturer in Puerto Rico. The rate is 4% and is effective through December 31, 2027. We account for the excise tax as a manufacturing cost that is capitalized in inventory and expensed in cost of sales when the related products are sold. For U.S. income tax purposes, the excise tax results in foreign tax credits that are generally recognized in our provision for income taxes when the excise tax is incurred. One or more of our legal entities file income tax returns in the U.S. federal jurisdiction, various U.S. state jurisdictions and certain foreign jurisdictions. Our income tax returns are routinely audited by the tax authorities in those jurisdictions. Significant disputes may arise with authorities involving issues of the timing and amount of deductions, the use of tax credits and allocations of income and expenses among various tax jurisdictions because of differing interpretations of tax laws, regulations and the interpretation of the relevant facts. As previously disclosed, we received a Revenue Agent Report (RAR) from the Internal Revenue Service (IRS) for the years 2010, 2011 and 2012. The RAR proposes to make significant adjustments that relate primarily to the allocation of profits between certain of our entities in the United States and the U.S. territory of Puerto Rico. We are in discussions with the IRS examination team and understand that the RAR may be modified. We disagree with the proposed adjustments and are pursuing resolution through the IRS administrative appeals process, which we believe will likely not be concluded within the next 12 months. Final resolution of the IRS audit could have a material impact on our results of operations and cash flows if not resolved favorably, however, we believe our income tax reserves are appropriately provided for all open tax years. We are no longer subject to U.S. federal income tax examinations for years ended on or before December 31, 2009. In addition, we are currently under examination by a number of other state and foreign tax jurisdictions. During the three and nine months ended September 30, 2017, the gross amounts of our unrecognized tax benefits (UTBs) increased approximately $120 million and $345 million, respectively, as a result of tax positions taken during the current year. Substantially all of the UTBs as of September 30, 2017, if recognized, would affect our effective tax rate.

Income taxes

The effective tax rates for the three and nine months ended September 30, 2017, were 15.1% and 15.4%, respectively, compared with 16.6% and 15.9%, respectively, for the corresponding periods of the prior year. The effective rates differ from the federal statutory rates primarily as a result of indefinitely invested earnings of our foreign operations. We do not provide for U.S. income taxes on undistributed earnings of our foreign operations that are intended to be invested indefinitely outside the United States.

The decrease in our effective tax rate for the three months ended September 30, 2017, was due primarily to favorable tax impacts of changes in the jurisdictional mix of income and expenses, as well as discrete benefits associated with the impairment of our AMG 899 (formerly TA-8995) asset and the related release of contingent consideration liabilities connected with the acquisition of Dezima Pharma B.V. (Dezima) (see Note 8, Goodwill and other intangible assets and Note 11, Fair value measurement), offset partially by adjustments to certain federal tax credits and deductions.

The decrease in our effective tax rate for the nine months ended September 30, 2017, was due primarily to favorable tax impacts of changes in the jurisdictional mix of income and expenses, as well as discrete benefits associated with the effective settlement of certain state and federal tax matters, offset partially by lower tax benefits from share-based compensation payments and adjustments to certain federal tax credits and deductions.

The U.S. territory of Puerto Rico imposes an excise tax on the gross intercompany purchase price of goods and services from our manufacturer in Puerto Rico. The rate is 4% and is effective through December 31, 2027. We account for the excise tax as a manufacturing cost that is capitalized in inventory and expensed in cost of sales when the related products are sold. For U.S. income tax purposes, the excise tax results in foreign tax credits that are generally recognized in our provision for income taxes when the excise tax is incurred.

One or more of our legal entities file income tax returns in the U.S. federal jurisdiction, various U.S. state jurisdictions and certain foreign jurisdictions. Our income tax returns are routinely audited by the tax authorities in those jurisdictions. Significant disputes may arise with authorities involving issues of the timing and amount of deductions, the use of tax credits and allocations of income and expenses among various tax jurisdictions because of differing interpretations of tax laws, regulations and the interpretation of the relevant facts. As previously disclosed, we received a Revenue Agent Report (RAR) from the Internal Revenue Service (IRS) for the years 2010, 2011 and 2012. The RAR proposes to make significant adjustments that relate primarily to the allocation of profits between certain of our entities in the United States and the U.S. territory of Puerto Rico. We are in discussions with the IRS examination team and understand that the RAR may be modified. We disagree with the proposed adjustments and are pursuing resolution through the IRS administrative appeals process, which we believe will likely not be concluded within the next 12 months. Final resolution of the IRS audit could have a material impact on our results of operations and cash flows if not resolved favorably, however, we believe our income tax reserves are appropriately provided for all open tax years. We are no longer subject to U.S. federal income tax examinations for years ended on or before December 31, 2009. In addition, we are currently under examination by a number of other state and foreign tax jurisdictions.

During the three and nine months ended September 30, 2017, the gross amounts of our unrecognized tax benefits (UTBs) increased approximately $120 million and $345 million, respectively, as a result of tax positions taken during the current year. Substantially all of the UTBs as of September 30, 2017, if recognized, would affect our effective tax rate.