General General (Policies)	9 Months Ended
General General (Policies)	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (GAAP) for interim financial information, and with the rules and regulations of the U.S. Securities and Exchange Commission (SEC).
Consolidation, Policy	These unaudited condensed consolidated financial statements do not include all disclosures associated with the Company’s consolidated annual financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2017, and, accordingly, should be read in conjunction with the referenced annual report. In the opinion of management, all adjustments (all of which are normal and recurring in nature) considered necessary for a fair presentation have been included. All significant intercompany balances and transactions have been eliminated in consolidation.
Securities and Exchange Commission's (SEC) Disclosure Update and Simplification Project (DUSTR), Policy	Securities and Exchange Commission’s (SEC) Disclosure Update and Simplification Project (DUSTR) As part of the SEC’s Disclosure Update and Simplification Project, the SEC issued a final rule that eliminates or amends disclosure requirements that are redundant or outdated in light of changes in SEC requirements, US GAAP, IFRS or changes in technology or the business environment. As a result, certain amounts previously reported in the consolidated financial statements have been reclassified in the accompanying consolidated financial statements to conform to the current period’s presentation, primarily to change the presentation of (Loss) gain on sale of real estate on the Condensed Consolidated Statement of Operations for the three and nine months ended September 30, 2018 and 2017. The Company has included (Loss) gain on sale of real estate as a component of Operating Income to present gain and losses on sales of properties in accordance with Accounting Standards Codification (“ASC”) 360-10-45-5. The change was made for the prior periods as the Securities and Exchange Commission has eliminated Rule 3-15(a) of Regulation S-X as part of Release No. 33-10532; 34-83875; IC-33203, which had required REITs to present gain and losses on sale of properties outside of continuing operations in the income statement. In addition to the presentation change of (Loss) gain on real estate on the Condensed Consolidated Statement of Operations, the SEC also issued a requirement to present the changes in shareholders’ equity in the interim financial statements in quarterly reports on Form 10-Q. This amendment is not effective until after November 5, 2018, however, the Company has chosen to early adopt and has reflected changes in shareholders’ equity in the current quarter filing.
Reclassifications, Policy	Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation. In addition, an immaterial adjustment was made to reclassify certain prior period amounts from unearned revenue to the allowance for doubtful accounts. Finally, the Company reclassified certain assets for which ownership and title transferred at lease expiration from the classification of Capitalized leases into the respective asset classification on the Condensed Consolidated Balance Sheet as of September 30, 2018. This included reclassification of the gross cost and related accumulated depreciation.
Adoption of Highly Inflationary Accounting in Argentina, Policy	Adoption of Highly Inflationary Accounting in Argentina GAAP guidance requires the use of highly inflationary accounting for countries whose projected cumulative three-year inflation rate exceeds 100 percent. In the second quarter of 2018, published inflation indices indicated that the projected three-year cumulative inflation rate in Argentina exceeded 100 percent, and as of July 1, 2018, we adopted highly inflationary accounting for our subsidiary in Argentina. Under highly inflationary accounting, Argentina’s functional currency became the Australian dollar, the reporting and functional currency of the immediate parent company of the Argentina entity, and its income statement and balance sheet have been measured in Australian dollars using both current and historical rates of exchange prior to translation into U.S. dollars in consolidation. The impact of the change in functional currency to Australian dollars resulted in a remeasurement of historical earnings reflected in retained earnings, which was previously measured at the average Argentinian peso to USD exchange rates applicable to the period, and a related decrease to Accumulated Other Comprehensive Loss. This activity is reflected within 'Other' on the Statement of Shareholders’ Equity for the nine months ended September 30, 2018. After the initial measurement process described previously, the effect of changes in exchange rates on peso-denominated monetary assets and liabilities has been reflected in earnings in Foreign currency exchange gain (loss) and was not material. As of September 30, 2018, the net monetary assets of the Argentina subsidiary were immaterial. Additionally, the operating income of the Argentina subsidiary was less than 3.0 percent of our consolidated operating income for the three and nine months ended September 30, 2018 and 2017.