11)	Income Taxes

The Company’s effective tax rate for the three and six months ended June 30, 2017 was 23.8% and 21.2%, respectively. The effective tax rate for the three and six months ended June 30, 2017 and related income tax expense, was lower than the U.S. statutory tax rate mainly due to the geographic mix of income earned by the Company’s international subsidiaries being taxed at rates lower than the U.S. statutory tax rate, the deduction for domestic production activities and the windfall stock compensation tax benefit related to the adoption of a new accounting standard that became applicable during the first quarter of 2017. The Company’s effective tax rate for the three and six months ended June 30, 2016 was 25.5% and 26.0%, respectively. The effective tax rate for the three and six months ended June 30, 2016 was lower than the U.S. statutory tax rate primarily due to the geographic mix of income and profits earned by the Company’s international subsidiaries being taxed at rates lower than the U.S. statutory tax rate, the federal research credit and the deduction for domestic production activities, offset by non-deductible acquisition-related costs and state income taxes.

As of June 30, 2017, the total amount of gross unrecognized tax benefits, which excludes interest and penalties, was approximately $27,239. At December 31, 2016, the total amount of gross unrecognized tax benefits, which excludes interest and penalties, was approximately $25,465. As of June 30, 2017, if these benefits were recognized in a future period, the timing of which is not estimable, the net unrecognized tax benefit of $18,760, excluding interest and penalties, would impact the Company’s effective tax rate. The Company accrues interest expense, and if applicable, penalties, for any uncertain tax positions. Interest and penalties are classified as a component of income tax expense. As of June 30, 2017 and December 31, 2016, the Company had accrued interest on unrecognized tax benefits of approximately $444 and $491, respectively.

Over the next 12 months it is reasonably possible that the Company may recognize approximately $1,686 of previously net unrecognized tax benefits, excluding interest and penalties, related to various U.S. federal, state and foreign tax positions primarily as a result of the expiration of certain statutes of limitations.

The Company and its subsidiaries are subject to examination by U.S. federal, state and foreign tax authorities. The U.S. statute of limitations remains open for tax years 2013 through present. The statute of limitations for the Company’s tax filings in other jurisdictions varies between fiscal years 2008 through present. We also have certain federal credit carry-forwards and state tax loss and credit carry-forwards that are open to examination for tax years 2000 through the present.