Income Taxes:

9 Months Ended

Sep. 30, 2019

Income Tax Disclosure [Abstract]

Income Tax Disclosure [Text Block]

Income Taxes

Income taxes were accrued at an estimated effective tax rate of 19% and 14% for the three and nine months ended September 30, 2019, respectively, as compared to 85% and (4)% for the three and nine months ended September 30, 2018, respectively.

The effective tax rate for the three and nine months ended September 30, 2019 differs from the federal statutory rate of 21% principally because of the effect of the mix of U.S. and foreign incomes, state income taxes, global intangible low-taxed income ("GILTI") and tax credits, and by the following discrete tax items recognized during the interim periods:

• Excess tax benefits recognized on stock option exercises and the vesting of restricted stock units during the three and nine months ended September 30, 2019 of $0.3 million and $7.7 million, respectively.

• The revaluation of the contingent consideration during the nine months ended September 30, 2019 resulted in a tax expense of $11.4 million.

• The repatriation of certain intellectual property and assets from one of our foreign subsidiaries to the U.S. parent resulted in a net tax benefit of $3.8 million.

• A return-to-provision adjustment for the year ended December 31, 2018 included a tax expense of $2.2 million primarily due to changes in estimates for GILTI.

The effective tax rate for the three and nine months ended September 30, 2018 differs from the federal statutory rate of 21% principally because of the effect of the mix of U.S. and foreign incomes, state income taxes and tax credits. The effective tax rate during the three and nine months ended September 30, 2018 included a discrete tax benefit of $1.6 million and $12.8 million, respectively, related to the excess tax benefits recognized on stock option exercises and the vesting of restricted stock units during the period. The effective tax rate for the nine months ended September 30, 2018 was also impacted by a contract settlement. The contract settlement resulted in a discrete tax benefit of $5.7 million.