Income Taxes	6 Months Ended
Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company calculates its interim income tax provision in accordance with ASC 270, Interim Reporting, and ASC 740, Accounting for Income Taxes (together, “ASC 740”). At the end of each interim period, the Company estimates its annual effective tax rate and applies that rate to its ordinary quarterly earnings to calculate the tax related to ordinary income. The tax effects for other items that are excluded from ordinary income are discretely calculated and recognized in the period in which they occur. On December 22, 2017, the Tax Cuts and Jobs Act (the "Tax Act") was enacted into legislation, which includes a broad range of provisions affecting businesses. The Tax Act significantly revises how companies compute their U.S. corporate tax liability by, among other provisions, reducing the corporate tax rate from 35% to 21% for tax years beginning after December 31, 2017, implementing a territorial tax system, and requiring a mandatory one-time tax on U.S.-owned undistributed foreign earnings and profits known as the transition tax. The Company recognized income tax benefit of $5.8 million and $2.0 million for the three months ended June 30, 2018 and 2017 respectively, which represents an effective tax rate of 65% and 14%, respectively. The Company recognized income tax benefit of $1.0 million and income tax expense of $0.2 million for the six months ended June 30, 2018 and 2017, respectively, which represents an effective tax rate of (3)% and 6% respectively. The effective tax rate for the three and six month periods ended June 30, 2018 differed from the same periods in prior years due primarily to reduction in the tax rate from the Tax Act, the impacts of the Company's full valuation allowance on U.S. earnings and higher discrete tax benefits recorded during the 2018 periods for excess tax benefits of stock-based compensation. The Company is subject to periodic audits by domestic and foreign tax authorities. Due to the carryforward of unutilized net operating loss and credit carryovers, the Company's federal tax years from 2009 and forward are subject to examination by the U.S. authorities. The Company's state and foreign tax years for 2001 and forward are subject to examination by applicable tax authorities. The Company believes that it has appropriate support for the income tax positions taken on its tax returns and that its accruals for tax liabilities are adequate for all open years based on an assessment of many factors, including past experience and interpretations of tax laws applied to the facts of each matter. On December 22, 2017, the Securities and Exchange Commissions issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Act. As of December 31, 2017, the Company was able to reasonably estimate certain effects of the Tax Act and, therefore, recorded provisional adjustments associated with the deemed repatriation transition tax and rate change revaluation of the deferred tax assets. The Company has not made any additional measurement-period adjustments related to these items during the three and six months ended June 30, 2018, as the Company is still awaiting relevant guidance as to certain provisions included in the Tax Act. However, the Company is continuing to gather additional information to complete the accounting for these items and expects to complete the accounting within the prescribed measurement period. Any subsequent adjustment to the amounts previously recorded in 2017 (the period of enactment of the Tax Act) will be a tax expense/benefit in the quarter of 2018 when the analysis is complete.

Income Taxes

The Company calculates its interim income tax provision in accordance with ASC 270, Interim Reporting, and ASC 740, Accounting for Income Taxes (together, “ASC 740”). At the end of each interim period, the Company estimates its annual effective tax rate and applies that rate to its ordinary quarterly earnings to calculate the tax related to ordinary income. The tax effects for other items that are excluded from ordinary income are discretely calculated and recognized in the period in which they occur.

On December 22, 2017, the Tax Cuts and Jobs Act (the "Tax Act") was enacted into legislation, which includes a broad range of provisions affecting businesses. The Tax Act significantly revises how companies compute their U.S. corporate tax liability by, among other provisions, reducing the corporate tax rate from 35% to 21% for tax years beginning after December 31, 2017, implementing a territorial tax system, and requiring a mandatory one-time tax on U.S.-owned undistributed foreign earnings and profits known as the transition tax.

The Company recognized income tax benefit of $5.8 million and $2.0 million for the three months ended June 30, 2018 and 2017 respectively, which represents an effective tax rate of 65% and 14%, respectively. The Company recognized income tax benefit of $1.0 million and income tax expense of $0.2 million for the six months ended June 30, 2018 and 2017, respectively, which represents an effective tax rate of (3)% and 6% respectively. The effective tax rate for the three and six month periods ended June 30, 2018 differed from the same periods in prior years due primarily to reduction in the tax rate from the Tax Act, the impacts of the Company's full valuation allowance on U.S. earnings and higher discrete tax benefits recorded during the 2018 periods for excess tax benefits of stock-based compensation.

The Company is subject to periodic audits by domestic and foreign tax authorities. Due to the carryforward of unutilized net operating loss and credit carryovers, the Company's federal tax years from 2009 and forward are subject to examination by the U.S. authorities. The Company's state and foreign tax years for 2001 and forward are subject to examination by applicable tax authorities. The Company believes that it has appropriate support for the income tax positions taken on its tax returns and that its accruals for tax liabilities are adequate for all open years based on an assessment of many factors, including past experience and interpretations of tax laws applied to the facts of each matter.

On December 22, 2017, the Securities and Exchange Commissions issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Act. As of December 31, 2017, the Company was able to reasonably estimate certain effects of the Tax Act and, therefore, recorded provisional adjustments associated with the deemed repatriation transition tax and rate change revaluation of the deferred tax assets. The Company has not made any additional measurement-period adjustments related to these items during the three and six months ended June 30, 2018, as the Company is still awaiting relevant guidance as to certain provisions included in the Tax Act. However, the Company is continuing to gather additional information to complete the accounting for these items and expects to complete the accounting within the prescribed measurement period. Any subsequent adjustment to the amounts previously recorded in 2017 (the period of enactment of the Tax Act) will be a tax expense/benefit in the quarter of 2018 when the analysis is complete.