Income Taxes:	9 Months Ended
Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes Income taxes were accrued at an estimated effective tax rate of 5% and 10% for the three and nine months ended September 30, 2020, respectively, as compared to 19% and 14% for the three and nine months ended September 30, 2019, respectively. The effective tax rate for the three and nine months ended September 30, 2020 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"), foreign-derived intangible income ("FDII"), tax credits and 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, 2020 of $0.1 million and $3.6 million, respectively. •The revaluation of the contingent consideration during the three and nine months ended September 30, 2020, which resulted in a tax benefit of $0.7 million and $1.1 million, respectively. •U.S. federal and state return-to-provision adjustments net of related reserve changes for the year ended December 31, 2019 resulted in a tax benefit of $3.8 million primarily due to changes in estimates for GILTI, FDII, and related foreign tax credits. 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, GILTI and tax credits and 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.

Income Taxes:

9 Months Ended

Sep. 30, 2020

Income Taxes

Income taxes were accrued at an estimated effective tax rate of 5% and 10% for the three and nine months ended September 30, 2020, respectively, as compared to 19% and 14% for the three and nine months ended September 30, 2019, respectively.

The effective tax rate for the three and nine months ended September 30, 2020 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"), foreign-derived intangible income ("FDII"), tax credits and 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, 2020 of $0.1 million and $3.6 million, respectively.

•The revaluation of the contingent consideration during the three and nine months ended September 30, 2020, which resulted in a tax benefit of $0.7 million and $1.1 million, respectively.

•U.S. federal and state return-to-provision adjustments net of related reserve changes for the year ended December 31, 2019 resulted in a tax benefit of $3.8 million primarily due to changes in estimates for GILTI, FDII, and related foreign tax credits.

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, GILTI and tax credits and 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.