Income Taxes	9 Months Ended
Sep. 30, 2019
Income Taxes
Income Taxes	10. Income Taxes Our effective income tax rate (ETR) for the nine months ended September 30, 2019 and 2018 was 33 percent and 21 percent, respectively. We recognized a loss before income taxes, and a corresponding income tax benefit, for the nine months ended September 30, 2019, as a result of the one-time $800.0 million payment to Arena in January 2019. As a result of this loss, our anticipated tax credits and foreign sales deduction, partially offset by non-deductible compensation expense, increased our tax benefit and resulting ETR for the nine months ended September 30, 2019 compared to the nine months ended September 30, 2018. Deferred tax assets increased by $172.4 million as of September 30, 2019 compared to December 31, 2018 primarily due to the amount of the Arena payment that will not be deductible for tax purposes in 2019. Our unrecognized tax benefits were $0.9 million for the nine months ended September 30, 2019 and September 30, 2018, and included $0.7 million of tax benefits that, if recognized, would impact our ETR. We record interest and penalties related to uncertain tax positions as a component of income tax expense. As of September 30, 2019, and 2018, we have not accrued any material interest expense related to uncertain tax positions. We are unaware of any material positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease within the next twelve months.

Income Taxes

9 Months Ended

Sep. 30, 2019

10. Income Taxes

Our effective income tax rate (ETR) for the nine months ended September 30, 2019 and 2018 was 33 percent and 21 percent, respectively. We recognized a loss before income taxes, and a corresponding income tax benefit, for the nine months ended September 30, 2019, as a result of the one-time $800.0 million payment to Arena in January 2019. As a result of this loss, our anticipated tax credits and foreign sales deduction, partially offset by non-deductible compensation expense, increased our tax benefit and resulting ETR for the nine months ended September 30, 2019 compared to the nine months ended September 30, 2018. Deferred tax assets increased by $172.4 million as of September 30, 2019 compared to December 31, 2018 primarily due to the amount of the Arena payment that will not be deductible for tax purposes in 2019.

Our unrecognized tax benefits were $0.9 million for the nine months ended September 30, 2019 and September 30, 2018, and included $0.7 million of tax benefits that, if recognized, would impact our ETR. We record interest and penalties related to uncertain tax positions as a component of income tax expense. As of September 30, 2019, and 2018, we have not accrued any material interest expense related to uncertain tax positions. We are unaware of any material positions for which it is reasonably possible that the total amounts of unrecognized tax benefits will significantly increase or decrease within the next twelve months.