BASIS OF PRESENTATION (Policies)	3 Months Ended
BASIS OF PRESENTATION (Policies)	Mar. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	The accompanying consolidated financial statements were prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) and, in the opinion of management, include all normal and recurring adjustments necessary to present fairly the results of the interim periods shown. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted pursuant to such SEC rules and regulations. Management believes that the disclosures made are adequate to make the information presented not misleading. Due to seasonality and other factors, the results for the interim periods may not be indicative of results for the full year. The financial statements contained herein should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2018 Annual Report on Form 10-K. The consolidated financial statements include the accounts of the Company and its subsidiaries. Also included in the consolidated financial statements are entities for which the Company has a controlling financial interest or is the primary beneficiary. Investments in companies in which the Company owns 20% to 50% of the voting common stock or otherwise exercises significant influence over operating and financial policies of the company are accounted for under the equity method. All significant intercompany transactions are eliminated in the consolidation process.
New Accounting Pronouncements Recently Adopted and Not Yet Adopted	New Accounting Pronouncements Recently Adopted Leases The Company adopted ASU No. 2016-02, which created ASC 842, Leases, and all subsequent ASUs relating to this Topic, as of January 1, 2019 (collectively, "ASC 842"). This new lease accounting standard, which supersedes previous lease accounting guidance under U.S. GAAP, results in significant changes to the balance sheets of lessees, most significantly by requiring the recognition of a right-of-use ("ROU") asset and lease liability by lessees for those leases classified as operating leases. Lessor accounting is also updated to align with certain changes in the lessee model and the revenue recognition standard ("ASC Topic 606"), which was adopted in 2018. The Company applied the transition provisions of this standard at January 1, 2019 following the optional transition method provided by ASU No. 2018-11; consequently, the consolidated financial statements and notes to the consolidated financial statements for periods before the date of adoption continue to be presented in accordance with ASC Topic 840. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the new standard, which allowed us to not reassess whether expired or existing contracts are or contain leases and to carry forward the historical lease classification for those leases that commenced prior to the date of adoption. Upon adoption of ASC 842, prepaid and deferred rent balances, which were historically presented separately, were combined and presented net within the ROU asset. Additionally, deferred gains related to previous transactions that were historically accounted for as sale and operating leasebacks in accordance with ASC Topic 840 were recognized as a cumulative-effect adjustment to equity, resulting in an increase to equity, net of tax, of $128.9 million. Under ASC Topic 840, such gains were recognized ratably over the lease term as a credit to operating lease expense, and operating lease expense for the three months ended March 31, 2018 included a credit of $1.5 million for the amortization of these gains, which was not recognized in the three months ended March 31, 2019. Adoption of the new standard had a material impact on our consolidated balance sheets, but it did not have a material impact on our other consolidated financial statements. Additionally, the standard requires disclosures to meet the objective of enabling users of the financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. Refer to Note 2, Revenue, and Note 3, Leases, for more information. Intangible Assets and Goodwill During the first quarter of 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350). This update eliminates the requirement to calculate the implied fair value of goodwill to measure a goodwill impairment charge. Entities will record an impairment charge based on the excess of a reporting unit's carrying amount over its fair value. The standard is effective for annual and any interim impairment tests performed for periods beginning after December 15, 2019. The Company early adopted the proposed guidance under ASU 2017-04 beginning on January 1, 2019 on a prospective basis. The implementation of ASU 2017-04 did not have a material impact on our consolidated financial statements and related disclosures. During the third quarter of 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40), Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract. This update requires that a customer in a cloud computing arrangement that is a service contract follow the internal use software guidance in Accounting Standards Codification (ASC) 350-402 to determine which implementation costs to capitalize as assets. The standard is effective for fiscal years beginning after December 15, 2019. The Company early adopted the proposed guidance under ASU 2017-04 beginning on January 1, 2019 on a prospective basis. The implementation of ASU 2017-04 did not have a material impact on our consolidated financial statements and related disclosures.
Revenue Recognition	Lease Revenue Considerations in Outdoor Segments Certain of the revenue transactions in the Americas outdoor and International outdoor segments are considered leases, for accounting purposes, as the contracts convey to customers the right to control the use of the Company’s advertising displays for a period of time. These contracts, which typically cover periods of a few weeks to one year (although there are some with longer terms), are generally cancelable after a specified notice period in the Americas outdoor segment, while contracts in the International outdoor segment are generally non-cancelable or require the customer to pay a fee to terminate the contract. To qualify as a lease, fulfillment of the contract must be dependent upon the use of a specified advertising structure, the customer must have almost exclusive use of the advertising display throughout the contract term, and, upon adoption of the new leases standard (ASC 842) on January 1, 2019, the customer must also have the right to change the advertisement that is displayed throughout the contract term. The Company has elected a practical expedient to not separate non-lease components from associated lease components if certain criteria are met. As such, each right to control the use of an advertising display that meets the lease criteria is combined with the related installation and maintenance services provided under the contract into a single lease component. Production services, which do not meet the criteria to be combined, and each advertising display that does not meet the lease criteria (along with any related installation and maintenance services) are non-lease components. Consideration in outdoor advertising contracts is allocated between lease and non-lease components in proportion to their relative standalone selling prices, which are generally approximated by the contractual prices for each promised service. The Company accounts for revenue from leases, which are all classified as operating leases, in accordance with the lease accounting guidance (ASC Topic 840 or ASC Topic 842, depending on the advertising campaign start date), while the Company’s remaining revenue transactions are accounted for as revenue from contracts with customers (ASC Topic 606). In accordance with the transition approach that the Company elected to adopt ASC Topic 842, as described in Note 1, revenue contracts with campaign start dates prior to January 1, 2019 were not reassessed to determine whether they qualify as a lease under the requirements of the new leasing standard. Instead, they continue to be accounted for as revenue from contracts with customers or revenue from leases based on the requirements of the previous standard (ASC Topic 840), and the new requirements have been applied to revenue contracts with campaign start dates on or after January 1, 2019. Because the definition of a lease is more restrictive under the new standard, fewer of our new outdoor advertising contracts meet the definition of a lease for accounting purposes, resulting in an increase in the percentage of revenue that is categorized as revenue from contracts with customers as compared to the prior year.