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Summary of Significant Accounting Policies (Narrative) (Details) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 12 Months Ended |  |  |
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Dec. 07, 2023 $ / shares | Nov. 16, 2023 $ / shares | Sep. 27, 2023 $ / shares | May 09, 2023 $ / shares | Mar. 01, 2023 $ / shares | Jan. 13, 2023 USD ($) | Dec. 07, 2022 $ / shares | Oct. 21, 2022 USD ($) | Sep. 20, 2022 $ / shares | Jul. 01, 2022 USD ($) | Jun. 06, 2022 $ / shares | Apr. 08, 2022 USD ($) | Mar. 01, 2022 $ / shares | Jan. 14, 2022 USD ($) | Dec. 14, 2021 $ / shares | Oct. 22, 2021 USD ($) | Sep. 28, 2021 $ / shares | Jul. 16, 2021 USD ($) | Jun. 18, 2021 $ / shares | Dec. 31, 2023 USD ($) segment $ / shares shares | Dec. 31, 2022 USD ($) $ / shares shares | Dec. 31, 2021 USD ($) $ / shares shares | Dec. 31, 2023 USD ($) | Dec. 31, 2023 | Dec. 31, 2023 item | Dec. 31, 2020 USD ($) | Mar. 31, 2013 USD ($)
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of market serving |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 27 | 27 |  |
Number of FM radio stations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 79 |  |  |  |  |  |  |
Number of AM radio stations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 33 |  |  |  |  |  |  |
Number of metro signals |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 80 |  |  |  |  |  |  |
Antidilutive securities excluded from computation of earnings per share, amount | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | 0 | 0 |  |  |  |  |
Time deposits |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 |  | $ 0 |  |  |  |
Securities at amortized cost |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10,100,000 |  | 10,600,000 |  |  |  |
Securities at fair value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10,000,000.0 |  | 10,600,000 |  |  |  |
Write-off of debt issuance costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 36,000 | 10,000 | $ 37,000 |  |  |  |  |
Net book value of deferred costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 166,000 |  | 130,000 |  |  |  |
Treasury stock shares acquired | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 11,274 | 6,044 | 16,577 |  |  |  |  |
Treasury stock acquired, average cost per share | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20.12 | $ 24.27 | $ 26.25 |  |  |  |  |
Number of broadcast licenses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 112 |  |  |
Allowance for doubtful accounts receivable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 519,000 | $ 469,000 | 618,000 |  |  | $ 648,000 |
Dividends declared per share (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 3.00 | $ 4.86 | $ 0.98 |  |  |  |  |
Cash dividends paid |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 3,990,000 |  | $ 960,000 |  | $ 960,000 |  | $ 19,875,000 | $ 19,785,000 | $ 1,914,000 |  |  |  |  |
Number of operating segments | segment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |
Number of reportable segments | segment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |
Class A Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock repurchase program, remaining authorization amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 18,000,000.0 |  |  |  |
Dividends declared per share (in dollars per share) | $ / shares | $ 2.00 | $ 0.25 | $ 0.25 | $ 0.25 | $ 0.25 |  | $ 0.25 |  | $ 0.25 |  |  |  |  |  | $ 0.16 |  |  |  |  |  |  |  |  |  |  |  |
Special cash dividend (in dollars per share) | $ / shares |  |  |  |  |  |  | $ 2.00 |  | $ 2.00 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash dividends paid |  |  |  |  |  | $ 13,800,000 |  | $ 13,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class B Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends declared per share (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.16 |  |  |  |  |  |  |  |  |  |  |  |
Common Class A and Common Class B |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends declared per share (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  | $ 0.20 |  | $ 0.16 |  |  |  | $ 0.16 |  | $ 0.16 |  |  |  |  |  |  |  |
Special cash dividend (in dollars per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.50 |  |  |  |  |  |  |  |  |  |  |  |
Cash dividends paid |  |  |  |  |  |  |  |  |  | $ 1,200,000 |  | $ 970,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Customer relationships |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Useful life |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3 years |  |  |  |  |  |  |
Continuing Operations |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Depreciation |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,013,000 | 5,133,000 | 5,362,000 |  |  |  |  |
Advertising and promotion costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,705,000 | $ 1,646,000 | $ 1,396,000 |  |  |  |  |
Revenue from Rights Concentration Risk | Revenue Benchmark | Top Five Markets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Concentration risk, market risk |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 36.00% | 38.00% | 39.00% |  |  |  |  |
Minimum | Class A Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share repurchase program, authorized amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 60,000,000
Minimum | Lease Agreements |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Useful life |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 year |  |  |  |  |  |  |
Minimum | Other intangibles |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Useful life |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 year |  |  |  |  |  |  |
Maximum | Class A Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Share repurchase program, authorized amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 75,800,000
Maximum | Lease Agreements |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Useful life |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 26 years |  |  |  |  |  |  |
Maximum | Other intangibles |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Useful life |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 15 years |  |  |  |  |  |  |

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