Income Taxes	3 Months Ended
Mar. 31, 2020
Income Taxes
Income Taxes	Note 13. Income Taxes Income tax expense was $1.0 million for the three months ended March 31, 2020, compared to $0.5 million the three months ended March 31, 2019. The $0.5 million increase was primarily due to a $5.7 million increase in pretax income, which was slightly offset by excess tax benefits associated with stock option exercises for the three months ended March 31, 2020, compared to the three months ended March 31, 2019. We had $66.6 million and $68.1 million of net deferred tax assets worldwide relating to net operating loss carryforwards, tax credit carryforwards and other temporary differences, as of March 31, 2020 and December 31, 2019, respectively. These deferred tax assets are available to reduce income taxes in future years. We have a $9.1 million valuation allowance in the U.S. against certain tax credits and state net operating losses due to the uncertainty of their realization based on long-term Company forecasts and the expiration dates on these tax assets. If future operating results of the U.S. or these foreign jurisdictions are significantly less than our expectations, it is reasonably possible that we would be required to record an additional valuation allowance on our deferred tax assets in the future.

Note 13. Income Taxes

Income tax expense was $1.0 million for the three months ended March 31, 2020, compared to $0.5 million the three months ended March 31, 2019. The $0.5 million increase was primarily due to a $5.7 million increase in pretax income, which was slightly offset by excess tax benefits associated with stock option exercises for the three months ended March 31, 2020, compared to the three months ended March 31, 2019.

We had $66.6 million and $68.1 million of net deferred tax assets worldwide relating to net operating loss carryforwards, tax credit carryforwards and other temporary differences, as of March 31, 2020 and December 31, 2019, respectively. These deferred tax assets are available to reduce income taxes in future years. We have a $9.1 million valuation allowance in the U.S. against certain tax credits and state net operating losses due to the uncertainty of their realization based on long-term Company forecasts and the expiration dates on these tax assets. If future operating results of the U.S. or these foreign jurisdictions are significantly less than our expectations, it is reasonably possible that we would be required to record an additional valuation allowance on our deferred tax assets in the future.