Nature of Business, Interim Financial Data and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Cumulus Media Inc. (and its consolidated subsidiaries, except as the context may otherwise require, “CUMULUS MEDIA,” “we,” “us,” “our,” or the “Company”) is a Delaware corporation, organized in 2018, and successor to a Delaware corporation with the same name that had been organized in 2002.
Basis of Presentation	Basis of Presentation As previously disclosed, on November 29, 2017 (the “Petition Date”), CM Wind Down Topco Inc. (formerly known as Cumulus Media Inc.), a Delaware corporation (“Old Cumulus”) and certain of its direct and indirect subsidiaries (collectively, the “Debtors”) filed voluntary petitions for relief (the “Bankruptcy Petitions”) under Chapter 11 of Title 11 of the United States Code (the “Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of New York (the “Bankruptcy Court”). The Debtors’ chapter 11 cases (the "Chapter 11 Cases") were jointly administered under the caption In re Cumulus Media Inc., et al, Case No. 17-13381. On May 10, 2018, the Bankruptcy Court entered the Findings of Fact, Conclusions of Law and Order Confirming the Debtors’ First Amended Joint Chapter 11 Plan of Reorganization [Docket No. 769] (the “Confirmation Order”), which confirmed the First Amended Joint Plan of Reorganization of Cumulus Media Inc. and its Debtor Affiliates Pursuant to Chapter 11 of the Bankruptcy Code [Docket No. 446] (the “Plan”), as modified by the Confirmation Order. On June 4, 2018 (the “Effective Date”), Old Cumulus satisfied the conditions to effectiveness set forth in the Confirmation Order and in the Plan, the Plan was substantially consummated, and Old Cumulus and the other Debtors emerged from Chapter 11. On June 29, 2018, the Bankruptcy Court entered an order closing the Chapter 11 Cases of all of the Debtors other than Old Cumulus, whose case will remain open until its estate has been fully administered including resolving outstanding claims and the Bankruptcy Court enters an order closing its case. In connection with its emergence, Old Cumulus implemented a series of internal reorganization transactions authorized by the Plan pursuant to which it transferred substantially all of its remaining assets to an indirectly wholly owned subsidiary of reorganized Cumulus Media Inc. (formerly known as CM Emergence Newco Inc.), a Delaware corporation (“CUMULUS MEDIA” or the “Company”), prior to winding down its business. References to “Successor” or “Successor Company” relate to CUMULUS MEDIA on and subsequent to June 4, 2018. References to “Predecessor”, “Predecessor Company” or “Old Cumulus” refer to Cumulus Media Inc. prior to June 4, 2018. Upon emergence from Chapter 11 on the Effective Date, the Company applied Accounting Standards Codification (“ASC”) 852 - Reorganizations (“ASC 852”) in preparing its consolidated financial statements. As a result of the application of fresh start accounting and the effects of the implementation of the Plan, a new entity for financial reporting purposes was created, and consequently the consolidated financial statements on and after June 4, 2018 generally are not comparable to the consolidated financial statements prior to that date. The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Interim Financial Data In the opinion of management, the Company's unaudited condensed consolidated financial statements include all adjustments of a normal recurring nature necessary for a fair statement of the results for the interim periods presented. The results for the interim periods are not necessarily indicative of those for the full year. The condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2018. Revision of Previously Issued Financial Statements During the third quarter of 2018, the Company determined that it had an error in the classification of certain content related costs in the Condensed Consolidated Statement of Operations disclosed in previous periods. The Company should have presented the amounts within Content costs rather than within Selling, general and administrative expenses. In the accompanying Condensed Consolidated Statement of Operations, the previous period has been revised to correct this misclassification. This reclassification resulted in an increase in Content costs of $4.2 million and a corresponding decrease in Selling, general and administrative expenses for the Predecessor Company period January 1, 2018 through June 3, 2018. The correction was not material to the consolidated financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles ("GAAP") requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosures of contingent assets and liabilities. On an on-going basis, the Company evaluates its estimates, including significant estimates related to revenue recognition, bad debts, intangible assets, income taxes, stock-based compensation, contingencies, litigation, valuation assumptions for impairment analysis, certain expense accruals, leases and, if applicable, purchase price allocations. The Company bases its estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances. Actual amounts and results may differ materially from these estimates.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) includes net income (loss) and certain items that are excluded from net income (loss) and recorded as a separate component of stockholders' equity (deficit). During the three and six months ended June 30, 2019 (Successor Company) and periods from January 1, 2018 through June 3, 2018 (Predecessor Company), and June 4, 2018 through June 30, 2018 (Successor Company), the Company had no items of other comprehensive income (loss) and, therefore, comprehensive income (loss) does not differ from reported net income (loss).
Assets Held for Sale	Assets Held for Sale During the year ended December 31, 2015, the Company entered into an agreement to sell certain land in the Company's Washington, DC market ("DC Land") to a third party. The sale is subject to various conditions and approvals, including, without limitation, the receipt by the buyer of certain required permits and approvals for its expected use of the land. There can be no assurance that such sale will be completed in a timely manner, at the original agreed price, or at all. On April 15, 2019, the Company announced that it had entered into an agreement to sell KLOS-FM in Los Angeles, CA to Meruelo Media ("Meruelo Sale"). On June 27, 2019, the Company announced that it had entered into an agreement to sell WABC-AM in New York, NY to Red Apple Media, Inc. ("WABC Sale"). The Meruelo Sale closed on July 15, 2019. The closing of the WABC Sale is subject to various conditions and regulatory approvals which remain pending. The Company expects the WABC Sale to close within the next twelve months.
Recent Accounting Standards Updates and Adoption of New Accounting Standards and Recent Accounting Standards Updates	Adoption of New Accounting Standards ASU 2016-02 - Leases (“ASU 2016-02”). In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, which provides updated guidance for the accounting for leases. This update requires lessees to recognize assets and liabilities for the rights and obligations created by leases with a term longer than one year. Leases will be classified as either financing or operating, thereby impacting the pattern of expense recognition in the statement of operations. In July 2018, the FASB issued ASU 2018-10 - Codification Improvements to Topic 842, Leases ("ASU 2018-10") and ASU 2018-11 - Targeted Improvements ("ASU 2018-11"), which provides technical corrections and clarification to ASU 2016-02. ASU 2016-02 and amendments ASU 2018-10 and ASU 2018-11 will be effective for fiscal years beginning after December 15, 2018, and interim periods thereafter. Early adoption is permitted. The standard requires the application of a modified retrospective approach by either applying the lease standard to each lease that existed at the beginning of the earliest comparative period presented in the financial statements, as well as leases that commenced after that date and recognizing a cumulative effect adjustment for leases that commenced prior to the beginning of the earliest comparative period presented, or applying the standard to the leases that commenced as of the beginning of the reporting period in which the entity first applies the leases standard with a cumulative effect adjustment as of that date. The Company adopted this standard on January 1, 2019 and elected the "package of practical expedients" and as a result did not recast existing leases prior to January 1, 2019. The new lease standard also provides as a practical expedient and an accounting policy election, the option to not separate non-lease components from the associated lease components and instead account for each separate lease component and its associated non-lease components as a single lease component. The Company elected this option both for leases under which it is the lessor and for leases under which it is the lessee. In adopting the new standard, the Company aggregated and evaluated lease arrangements, implemented new controls and processes, and installed a lease accounting system. Adoption of the new standard resulted in recording operating lease right-of-use assets and operating lease liabilities of approximately $156.1 million and $154.5 million on January 1, 2019. See Note 13 Leases for further information. ASU 2018-07 - Compensation - Stock Compensation (Topic 718): Improvements to Non-employee Share-Based Payment Accounting (“ASU 2018-07”). The standard aligns the accounting for share-based payment awards issued to employees and non-employees. Changes to the accounting for non-employee awards include: (1) equity-classified share-based payment awards issued to non-employees will now be measured on the grant date, instead of the previous requirement to re-measure the awards through the performance completion date; (2) for performance conditions, compensation cost associated with the award will be recognized when achievement of the performance condition is probable, rather than upon achievement of the performance condition; and (3) the current requirement to reassess the classification (equity or liability) for nonemployee awards upon vesting will be eliminated, except for awards in the form of convertible instruments. The guidance should be applied to all new awards granted after the date of adoption. In addition, the modified retrospective approach should be used on all liability-classified awards that have not been settled and equity-classified awards for which a measurement date has not been established by the adoption date by re-measurement at fair value as of the adoption date with a cumulative effect adjustment to opening retained earnings in the fiscal year of adoption. The standard is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company adopted ASU 2018-07 as of January 1, 2019 and there was no material impact to the Condensed Consolidated Financial Statements. Recent Accounting Standards Updates ASU 2016-13 - Financial Instruments - Credit Losses (Topic 326) (“ASU 2016-13”). In June 2016, the FASB issued ASU 2016-13 which requires entities to estimate loss of financial assets measured at amortized cost, including trade receivables, debt securities and loans, using an expected credit loss model. The expected credit loss differs from the previous incurred losses model primarily in that the loss recognition threshold of “probable” has been eliminated and that expected loss should consider reasonable and supportable forecasts in addition to the previously considered past events and current conditions. Additionally, the guidance requires additional disclosures related to the further disaggregation of information related to the credit quality of financial assets by year of the asset’s origination for as many as five years. Entities must apply the standard provision as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. The standard is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. Early adoption is permitted for annual periods beginning after December 15, 2018, and interim periods within those fiscal years. The Company is currently evaluating the potential impact of adopting ASU 2016-13 on its Consolidated Financial Statements. ASU 2018-13 - Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”). In August 2018, the FASB issued ASU 2018-13, which eliminates, adds, and modifies certain disclosure requirements for fair value measurements as part of its disclosure framework project. ASU 2018-13 is effective for all entities for fiscal years beginning after December 15, 2019, and interim periods therein, but entities are permitted to early adopt either the entire standard or only the provisions that eliminate or modify the requirements. The Company is currently evaluating the potential impact of adopting ASU 2018-13 on its Consolidated Financial Statements.