Income Taxes |
6 Months Ended |
|---|---|
Jun. 30, 2015 | |
| Income Tax Disclosure [Abstract] | |
| Income Taxes | Income Taxes Our provision for income taxes for interim periods is determined using an estimate of our annual effective tax rate and adjusted for discrete items, if any, in the relevant period. Each quarter we update our estimate of the annual effective tax rate, and if our estimated tax rate changes, we make a cumulative adjustment. Our effective tax rate is impacted by and differs from the federal statutory rate primarily due to non-deductible stock-based compensation and the adverse effect of losses incurred in certain foreign jurisdictions for which we do not realize a tax benefit. Our effective tax rate may also be adversely impacted by the amount of our income (loss) before income tax expense (benefit) relative to our income tax expense, non-deductible expenses and changes in tax law such as the expiration of the U.S. federal research and development credit at the end of 2014. Our effective tax rate was (2.1)% and (3.9)% for the three months ended June 30, 2015 and 2014, and 5.2% and (56.9)% for the six months ended June 30, 2015 and 2014, respectively. The difference in the effective tax rates between the six month periods is attributable to the change in the relationship between non-deductible tax items and the loss before income tax expense (benefit). These non-deductible tax items primarily include stock-based compensation and meals and entertainment expenses. The impact of adjustments to our effective tax rate for discrete items and non-deductible expenses is greater in periods close to break-even. During the six months ended June 30, 2015, we recognized an income tax benefit of $1.6 million, which includes $1.4 million of discrete tax benefits relating to disqualifying dispositions on incentive stock options. During the six months ended June 30, 2014, we recognized an income tax expense of $3.7 million, which included $1.0 million of discrete tax benefits relating to disqualifying dispositions on incentive stock options. We are currently under audit by the Internal Revenue Service ("IRS") for taxable years 2012 and 2013, which may lead to proposed adjustments to our taxes or net operating losses with respect to the years under examination as well as in subsequent periods that utilize these net operating losses. To date, we have not received any notices of proposed adjustments from the IRS related to this or any other examination periods. |