Income tax expense and the effective tax rate for the three and six months ended June 30, 2015 and 2014 were as follows (in thousands, except the effective tax rate):

The tax provision for the three and six months ended June 30, 2015 and 2014 was computed using the estimated effective tax rates applicable to each of the domestic and international taxable jurisdictions for the full year. The Company estimates its ongoing effective annual tax rate in 2015 to be between 21% and 25%, which is subject to management’s quarterly review and revision, if necessary.

The Company’s provision for income tax expense and effective income tax rate are significantly impacted by the mix of the Company’s domestic and foreign earnings (loss) before income taxes. In the foreign jurisdictions in which the Company has operations, the applicable statutory rates range from 0% to 34%, which is generally significantly lower than the U.S. federal and state combined statutory rate of approximately 39%. For the three and six months ended June 30, 2015, the decrease in the effective tax rate was primarily attributable to an increase in the amount of foreign earnings relative to domestic earnings as compared to the same period in the prior year.

As of June 30, 2015, the Company had approximately $513.9 million in cash and cash equivalents, of which $233.6 million, or 45.4%, was held outside the U.S. Of the $233.6 million held by the Company’s foreign subsidiaries, approximately $82.9 million is available for repatriation to the U.S. without incurring U.S. income taxes and applicable foreign income and withholding taxes in excess of the amounts accrued in the Company’s condensed consolidated financial statements as of June 30, 2015. Under current applicable tax laws, if the Company chooses to repatriate some or all of the funds designated as indefinitely reinvested outside the U.S., the amount repatriated would be subject to U.S. income taxes and applicable foreign income and withholding taxes. The Company does not expect to repatriate any of the funds presently designated as indefinitely reinvested outside the U.S. As such, the Company did not provide for deferred income taxes on its accumulated undistributed earnings of the Company’s foreign subsidiaries.