Income taxes	9 Months Ended
Sep. 30, 2017
Income taxes [Abstract]
Income taxes	6. Income taxes We recorded an income tax provision for the third quarter of 2017 of $769,000 at an effective tax rate of 29.8%, compared to an income tax provision during the third quarter of 2016 of $344,000 at an effective tax rate of 28.0%. For the nine months ended September 30, 2017, we recorded an income tax provision of $1,657,000 at an effective tax rate of 31.4%, compared to an income tax provision during the nine months ended September 30, 2016 of $1,010,000 at an effective tax rate of 30.9%. Our effective tax rate for the third quarter of 2017 was higher due to certain tax credits having less of an impact on significantly higher pre-tax income in the third quarter of 2017 compared to the third quarter of 2016. We are subject to U.S. federal income tax, as well as income tax in certain state and foreign jurisdictions. We have substantially concluded all U.S. federal income tax, state and local, and foreign tax regulatory examination matters through 2013. During 2013, an examination of our 2010 federal tax return was completed. However, our federal tax returns for the years 2014 through 2016 remain open to examination. Various state and foreign tax jurisdiction tax years remain open to examination as well, though we believe that any additional assessment would be immaterial to the Condensed Consolidated Financial Statements. No state or foreign tax jurisdiction income tax returns are currently under examination. As of September 30, 2017, we had $80,000 of total gross unrecognized tax benefits that, if recognized, would favorably affect the effective income tax rate in any future periods. During the third quarter of 2017, we recognized $31,000 of previously unrecognized tax benefits as the statute of limitations on the use of our 2013 R&D credits expired during the third quarter of 2017. We recognize interest and penalties related to uncertain tax positions in the income tax provision. As of September 30, 2017, we have $14,000 of accrued interest and penalties related to uncertain tax positions.

Income taxes

9 Months Ended

Sep. 30, 2017

6. Income taxes

We recorded an income tax provision for the third quarter of 2017 of $769,000 at an effective tax rate of 29.8%, compared to an income tax provision during the third quarter of 2016 of $344,000 at an effective tax rate of 28.0%. For the nine months ended September 30, 2017, we recorded an income tax provision of $1,657,000 at an effective tax rate of 31.4%, compared to an income tax provision during the nine months ended September 30, 2016 of $1,010,000 at an effective tax rate of 30.9%. Our effective tax rate for the third quarter of 2017 was higher due to certain tax credits having less of an impact on significantly higher pre-tax income in the third quarter of 2017 compared to the third quarter of 2016.

We are subject to U.S. federal income tax, as well as income tax in certain state and foreign jurisdictions. We have substantially concluded all U.S. federal income tax, state and local, and foreign tax regulatory examination matters through 2013. During 2013, an examination of our 2010 federal tax return was completed. However, our federal tax returns for the years 2014 through 2016 remain open to examination. Various state and foreign tax jurisdiction tax years remain open to examination as well, though we believe that any additional assessment would be immaterial to the Condensed Consolidated Financial Statements. No state or foreign tax jurisdiction income tax returns are currently under examination. As of September 30, 2017, we had $80,000 of total gross unrecognized tax benefits that, if recognized, would favorably affect the effective income tax rate in any future periods. During the third quarter of 2017, we recognized $31,000 of previously unrecognized tax benefits as the statute of limitations on the use of our 2013 R&D credits expired during the third quarter of 2017.

We recognize interest and penalties related to uncertain tax positions in the income tax provision. As of September 30, 2017, we have $14,000 of accrued interest and penalties related to uncertain tax positions.