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Summary of Significant Accounting Policies (Narrative) (Details) $ in Millions | 9 Months Ended |
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Sep. 30, 2024 USD ($) segment item | Dec. 31, 2023 USD ($)
Summary of Significant Accounting Policies |  |
Number of market serving | 28 |
Number of FM radio stations | 82 |
Number of AM radio stations | 32 |
Number of metro signals | 79 |
Debt securities, held to maturity | $ | $ 8.8 | $ 10.6
Securities at fair value | $ | $ 8.8 | $ 10.6
Number of Radio Markets | 28 |
Number of operating segments | segment | 1 |
Number of reportable segments | segment | 1 |

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- Definition Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity), classified as current. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481830/320-10-45-2 + Details
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