Income Taxes (Notes)	6 Months Ended
Jun. 30, 2018
Income Taxes [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes The lower effective income tax rate for the six months ended June 30, 2018 compared to the same period in 2017 is primarily due to the corporate tax rate reduction in the U.S. from enacted tax legislation commonly referred to as the Tax Cuts and Jobs Act ("TCJA"). The difference between the Company's overall tax rate and the U.S. statutory rate of 21 percent principally relates to state and local income taxes, net of federal income tax benefits, and the differences between tax rates in the various foreign jurisdictions in which the Company operates. In addition, the Company's first quarter results include a discrete income tax expense of approximately $0.4 million and an income tax benefit of approximately $0.9 million, in 2018 and 2017, respectively, related to employee share-based payment accounting. The TCJA was enacted in December 2017. ASC 740, Accounting for Income Taxes, requires companies to recognize the effects of tax law changes in the period of enactment. The TCJA makes broad and complex changes to the U.S. tax code including, but not limited to (1) reducing the U.S. federal corporate tax rate from 35 percent to 21 percent, (2) requiring a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries that may be paid over eight years, (3) accelerating expensing of certain capital expenditures, (4) eliminating or limiting certain deductions (interest, domestic production activities, and executive compensation), and (5) establishing global minimum income tax and base erosion tax provisions related to offshore activities and affiliated party payments. Due to the timing of the new tax law and the substantial changes it brings, the SEC staff 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 in reasonable detail to complete the accounting for the TCJA. The Company recognized the provisional tax impacts related to deemed repatriated earnings and the revaluation of deferred tax assets and liabilities in its consolidated financial statements for the year ended December 31, 2017. The Company has not changed these estimates during the six months ended June 30, 2018. The ultimate impact of the TCJA may differ from the provisional amounts, possibly materially, due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the TCJA. The accounting is expected to be completed within the one year measurement period allowed under SAB 118.

Income Taxes

The lower effective income tax rate for the six months ended June 30, 2018 compared to the same period in 2017 is primarily due to the corporate tax rate reduction in the U.S. from enacted tax legislation commonly referred to as the Tax Cuts and Jobs Act ("TCJA"). The difference between the Company's overall tax rate and the U.S. statutory rate of 21 percent principally relates to state and local income taxes, net of federal income tax benefits, and the differences between tax rates in the various foreign jurisdictions in which the Company operates. In addition, the Company's first quarter results include a discrete income tax expense of approximately $0.4 million and an income tax benefit of approximately $0.9 million, in 2018 and 2017, respectively, related to employee share-based payment accounting.

The TCJA was enacted in December 2017. ASC 740, Accounting for Income Taxes, requires companies to recognize the effects of tax law changes in the period of enactment. The TCJA makes broad and complex changes to the U.S. tax code including, but not limited to (1) reducing the U.S. federal corporate tax rate from 35 percent to 21 percent, (2) requiring a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries that may be paid over eight years, (3) accelerating expensing of certain capital expenditures, (4) eliminating or limiting certain deductions (interest, domestic production activities, and executive compensation), and (5) establishing global minimum income tax and base erosion tax provisions related to offshore activities and affiliated party payments.

Due to the timing of the new tax law and the substantial changes it brings, the SEC staff 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 in reasonable detail to complete the accounting for the TCJA. The Company recognized the provisional tax impacts related to deemed repatriated earnings and the revaluation of deferred tax assets and liabilities in its consolidated financial statements for the year ended December 31, 2017. The Company has not changed these estimates during the six months ended June 30, 2018. The ultimate impact of the TCJA may differ from the provisional amounts, possibly materially, due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the TCJA. The accounting is expected to be completed within the one year measurement period allowed under SAB 118.