Income Taxes	3 Months Ended
Mar. 31, 2013
Income Taxes	5. Income Taxes Income tax provisions for interim periods are based on estimated annual income tax rates, adjusted to reflect the effects of any significant infrequent or unusual items which are required to be discretely recognized within the current interim period. The Company’s intention is to permanently reinvest its foreign earnings outside of the United States. As a result, the effective tax rates in the periods presented are largely based upon the forecasted pre-tax earnings mix and allocation of certain expenses in various taxing jurisdictions where the Company conducts its business that apply a broad range of statutory income tax rates, certain of which are less than the U.S. statutory rate. The effective tax rate for the three months ended March 31, 2013 and March 31, 2012 was 21.3% and 27.8%, respectively. The effective tax rate for the three months ended March 31, 2013 included the marginal rate benefit of the U.S. Federal Research and Development Tax Credit (the “Federal R&D Tax Credit”) for 2013, as well as a one-time discrete $4 million tax benefit associated with the Federal R&D Tax Credit for 2012, which was retroactively reinstated with the enactment of the American Taxpayer Relief Act of 2012 in January of 2013. There were no material discrete tax items, nor any tax benefit associated with the 2012 Federal R&D Tax Credit due to its expiration, reflected in the effective tax rate for the three months ended March 31, 2012.

Income Taxes

3 Months Ended

Mar. 31, 2013

5. Income Taxes

Income tax provisions for interim periods are based on estimated annual income tax rates, adjusted to reflect the effects of any significant infrequent or unusual items which are required to be discretely recognized within the current interim period. The Company’s intention is to permanently reinvest its foreign earnings outside of the United States. As a result, the effective tax rates in the periods presented are largely based upon the forecasted pre-tax earnings mix and allocation of certain expenses in various taxing jurisdictions where the Company conducts its business that apply a broad range of statutory income tax rates, certain of which are less than the U.S. statutory rate.

The effective tax rate for the three months ended March 31, 2013 and March 31, 2012 was 21.3% and 27.8%, respectively. The effective tax rate for the three months ended March 31, 2013 included the marginal rate benefit of the U.S. Federal Research and Development Tax Credit (the “Federal R&D Tax Credit”) for 2013, as well as a one-time discrete $4 million tax benefit associated with the Federal R&D Tax Credit for 2012, which was retroactively reinstated with the enactment of the American Taxpayer Relief Act of 2012 in January of 2013. There were no material discrete tax items, nor any tax benefit associated with the 2012 Federal R&D Tax Credit due to its expiration, reflected in the effective tax rate for the three months ended March 31, 2012.