Income Taxes	6 Months Ended
Jun. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	5. Income Taxes The Company’s income tax provision for the three and six months ended June 30, 2017 and June 30, 2016 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, 2017 and June 30, 2016 is primarily related to foreign income taxes associated with our Canadian operations, changes in deferred tax liabilities associated with amortization of United States tax deductible goodwill, alternative minimum tax 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, 2017 and June 30, 2016, respectively. The Company has reflected any uncertain tax positions within its current taxes payable, but none in 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 2016 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 2016 remain subject to examination. The Company increased both its net operating loss deferred tax asset and its valuation allowance by $152,000 upon adoption of ASU No. 2016-09 relating to certain tax deductions associated with stock option transactions greater than the stock-related compensation expense for financial statement purposes.

5. Income Taxes

The Company’s income tax provision for the three and six months ended June 30, 2017 and June 30, 2016 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, 2017 and June 30, 2016 is primarily related to foreign income taxes associated with our Canadian operations, changes in deferred tax liabilities associated with amortization of United States tax deductible goodwill, alternative minimum tax 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, 2017 and June 30, 2016, respectively.

The Company has reflected any uncertain tax positions within its current taxes payable, but none in 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 2016 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 2016 remain subject to examination. The Company increased both its net operating loss deferred tax asset and its valuation allowance by $152,000 upon adoption of ASU No. 2016-09 relating to certain tax deductions associated with stock option transactions greater than the stock-related compensation expense for financial statement purposes.