Income Taxes	9 Months Ended
Sep. 30, 2013
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes. Our overall effective tax rate for the three months ended September 30, 2013 was 12.9%, compared to 20.0% for the corresponding period of 2012. For the nine months ended September 30, 2013, our effective tax rate was 14.0%, compared to 26.0% for the corresponding period of 2012. The effective income tax rates for the three and nine-month periods ended September 30, 2013, when compared to the corresponding periods of 2012, were lower as a result of a higher mix of earnings from our foreign operations, which are taxed at lower rates than our U.S. operations, and the release of reserves for uncertain tax positions due to statute of limitation expirations. In addition, the effective tax rate for the nine months ended September 30, 2013 was lower than the corresponding prior-year period due to the reinstatement of the federal research and development credit for the 2012 tax year. The credit was reinstated by the American Taxpayer Relief Act of 2012, which was signed on January 2, 2013. We recognized the federal research and development credit as a discrete benefit in the first quarter of 2013, the period in which the reinstatement was enacted.

Income Taxes

9 Months Ended

Sep. 30, 2013

Income Taxes. Our overall effective tax rate for the three months ended September 30, 2013 was 12.9%, compared to 20.0% for the corresponding period of 2012. For the nine months ended September 30, 2013, our effective tax rate was 14.0%, compared to 26.0% for the corresponding period of 2012. The effective income tax rates for the three and nine-month periods ended September 30, 2013, when compared to the corresponding periods of 2012, were lower as a result of a higher mix of earnings from our foreign operations, which are taxed at lower rates than our U.S. operations, and the release of reserves for uncertain tax positions due to statute of limitation expirations. In addition, the effective tax rate for the nine months ended September 30, 2013 was lower than the corresponding prior-year period due to the reinstatement of the federal research and development credit for the 2012 tax year. The credit was reinstated by the American Taxpayer Relief Act of 2012, which was signed on January 2, 2013. We recognized the federal research and development credit as a discrete benefit in the first quarter of 2013, the period in which the reinstatement was enacted.