Income Taxes	6 Months Ended
Jun. 30, 2013
Income Taxes	8. Income Taxes We estimate the annual effective income tax rate quarterly based on current annual forecasts. Items unrelated to current year ordinary income are recognized entirely in the period identified as a discrete item of tax. The quarterly income tax provision is comprised of tax on ordinary income provided at the most recent estimated annual effective tax rate increased or decreased for the tax effect of discrete items. For the six months ended June 30, 2013 and 2012, the estimated annual effective tax rate applied to ordinary income was 117.5% and 35.1%, respectively. Our effective tax rate for the three and six months ended June 30, 2013 benefited from a reduced state apportionment factor based upon year-to-date sales and 2013 research and development (“R&D”) tax credits. The effective tax rate for the six months ended June 30, 2013, which reflects federal and state taxable income also includes a net discrete tax benefit of $368,000 for 2012 R&D tax credits. The effective tax rate for the six months ended June 30, 2012 was positively affected by a net discrete tax benefit of $578,000 for state income taxes and R&D tax credits, partially offset by a net operating loss carryback. Including the effect of the discrete tax items, our effective tax rate for the six months ended June 30, 2013 and 2012 was 160.4% and 31.4%, respectively. For the three months ended June 30, 2013 and 2012, our effective tax rate was 231.7% and 33.0%, respectively.

Income Taxes

6 Months Ended

Jun. 30, 2013

8. Income Taxes

We estimate the annual effective income tax rate quarterly based on current annual forecasts. Items unrelated to current year ordinary income are recognized entirely in the period identified as a discrete item of tax. The quarterly income tax provision is comprised of tax on ordinary income provided at the most recent estimated annual effective tax rate increased or decreased for the tax effect of discrete items.

For the six months ended June 30, 2013 and 2012, the estimated annual effective tax rate applied to ordinary income was 117.5% and 35.1%, respectively. Our effective tax rate for the three and six months ended June 30, 2013 benefited from a reduced state apportionment factor based upon year-to-date sales and 2013 research and development (“R&D”) tax credits. The effective tax rate for the six months ended June 30, 2013, which reflects federal and state taxable income also includes a net discrete tax benefit of $368,000 for 2012 R&D tax credits. The effective tax rate for the six months ended June 30, 2012 was positively affected by a net discrete tax benefit of $578,000 for state income taxes and R&D tax credits, partially offset by a net operating loss carryback. Including the effect of the discrete tax items, our effective tax rate for the six months ended June 30, 2013 and 2012 was 160.4% and 31.4%, respectively. For the three months ended June 30, 2013 and 2012, our effective tax rate was 231.7% and 33.0%, respectively.