Income Taxes	6 Months Ended
Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	5. Income Taxes The Company’s income tax provision for the three and six months ended June 30, 2018 and June 30, 2017 reflects its estimate of the effective tax rates expected to be applicable for the full years, adjusted for any discrete events that are recorded in the period in which they occur. The estimates are re-evaluated each quarter based on the estimated tax expense for the full year. The tax provision for the three and six months ended June 30, 2018 and June 30, 2017 is primarily related to foreign income taxes associated with our Canadian, Irish, and Israeli operations, changes in deferred tax liabilities associated with amortization of United States tax deductible goodwill and state taxes in certain states in which the Company does not file on a consolidated basis or have net operating loss carryforwards. The Company has historically incurred operating losses in the United States and, given its cumulative losses and limited history of profits, has recorded a valuation allowance against its United States net deferred tax assets, exclusive of tax deductible goodwill, at June 30, 2018 and June 30, 2017, respectively. The Company has reflected any uncertain tax positions primarily within its long-term taxes payable and a portion within deferred taxes. Federal, state, and foreign income tax returns have been filed in jurisdictions with varying statutes of limitations. Varying among the separate companies, tax years 1998 through 2017 remain subject to examination by federal and most state tax authorities due to our net operating loss carryforwards. In foreign jurisdictions, tax years 2008 through 2017 remain subject to examination. The Tax Act enacted in December 2017 introduced significant changes to U.S. income tax law. Effective 2018, the Tax Act reduced the U.S. statutory tax rate from 35% to 21% and created new taxes on certain foreign-sourced earnings and certain intercompany payments. The Company is applying the guidance in SEC Staff Accounting Bulletin No. 118 when accounting for the enactment-date effects of the Tax Act. Due to the timing of the enactment and the complexity involved in applying the provisions of the Tax Act, we made reasonable estimates of the effects and recorded provisional amounts in our financial statements as of December 31, 2017. As we collect and prepare necessary data, and interpret the Tax Act and any additional guidance issued by the U.S. Treasury Department, the Internal Revenue Service (IRS), and other standard-setting bodies, we may make adjustments to the provisional amounts. Those adjustments may materially affect our provision for income taxes and effective tax rate in the period in which the adjustments are made. During the six months ended June 30, 2018, the Company did not recognize any adjustments to the provisional amounts recorded at December 31, 2017. The accounting for the tax effects of the Tax Act will be completed later in 2018. Under a provision commonly known as global intangible low taxes income (“GILTI”), the Tax Act subjects a U.S. shareholder to current tax on certain earnings of foreign subsidiaries. Under US GAAP, an accounting policy election can be made to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years, or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. Given the complexity of the GILTI provisions, the Company is still evaluating the effects of the GILTI provisions and has not yet made an accounting policy election. At June 30, 2018, because the Company is still evaluating the GILTI provisions, it has included GILTI related to current-year operations only in our estimated annual effective tax rate and has not provided additional GILTI on deferred items.

5. Income Taxes

The Company’s income tax provision for the three and six months ended June 30, 2018 and June 30, 2017 reflects its estimate of the effective tax rates expected to be applicable for the full years, adjusted for any discrete events that are recorded in the period in which they occur. The estimates are re-evaluated each quarter based on the estimated tax expense for the full year. The tax provision for the three and six months ended June 30, 2018 and June 30, 2017 is primarily related to foreign income taxes associated with our Canadian, Irish, and Israeli operations, changes in deferred tax liabilities associated with amortization of United States tax deductible goodwill and state taxes in certain states in which the Company does not file on a consolidated basis or have net operating loss carryforwards. The Company has historically incurred operating losses in the United States and, given its cumulative losses and limited history of profits, has recorded a valuation allowance against its United States net deferred tax assets, exclusive of tax deductible goodwill, at June 30, 2018 and June 30, 2017, respectively.

The Company has reflected any uncertain tax positions primarily within its long-term taxes payable and a portion within deferred taxes. Federal, state, and foreign income tax returns have been filed in jurisdictions with varying statutes of limitations. Varying among the separate companies, tax years 1998 through 2017 remain subject to examination by federal and most state tax authorities due to our net operating loss carryforwards. In foreign jurisdictions, tax years 2008 through 2017 remain subject to examination.

The Tax Act enacted in December 2017 introduced significant changes to U.S. income tax law. Effective 2018, the Tax Act reduced the U.S. statutory tax rate from 35% to 21% and created new taxes on certain foreign-sourced earnings and certain intercompany payments. The Company is applying the guidance in SEC Staff Accounting Bulletin No. 118 when accounting for the enactment-date effects of the Tax Act.

Due to the timing of the enactment and the complexity involved in applying the provisions of the Tax Act, we made reasonable estimates of the effects and recorded provisional amounts in our financial statements as of December 31, 2017. As we collect and prepare necessary data, and interpret the Tax Act and any additional guidance issued by the U.S. Treasury Department, the Internal Revenue Service (IRS), and other standard-setting bodies, we may make adjustments to the provisional amounts. Those adjustments may materially affect our provision for income taxes and effective tax rate in the period in which the adjustments are made. During the six months ended June 30, 2018, the Company did not recognize any adjustments to the provisional amounts recorded at December 31, 2017. The accounting for the tax effects of the Tax Act will be completed later in 2018.

Under a provision commonly known as global intangible low taxes income (“GILTI”), the Tax Act subjects a U.S. shareholder to current tax on certain earnings of foreign subsidiaries. Under US GAAP, an accounting policy election can be made to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years, or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. Given the complexity of the GILTI provisions, the Company is still evaluating the effects of the GILTI provisions and has not yet made an accounting policy election. At June 30, 2018, because the Company is still evaluating the GILTI provisions, it has included GILTI related to current-year operations only in our estimated annual effective tax rate and has not provided additional GILTI on deferred items.