Goodwill - Schedule of Changes in Goodwill (Detail) - USD ($) $ in Thousands  | 
3 Months Ended | 9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Sep. 30, 2023  | 
Sep. 30, 2022  | 
Sep. 30, 2023  | 
Sep. 30, 2022  | 
Dec. 31, 2022  | 
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| Goodwill [Line Items] | |||||
| Balance, beginning of period before cumulative loss on impairment | $ 28,975 | $ 28,749 | $ 28,749 | ||
| Accumulated loss on impairment | (4,890) | (4,763) | (4,763) | ||
| Balance, beginning of period after cumulative loss on impairment | 24,085 | 23,986 | 23,986 | ||
| Loss on impairment | $ (733) | $ 0 | (2,580) | $ (127) | (127) | 
| Balance, end of period before cumulative loss on impairment | 30,236 | 30,236 | 28,975 | ||
| Accumulated loss on impairment | (7,470) | (7,470) | (4,890) | ||
| Ending period balance | $ 22,766 | 22,766 | 24,085 | ||
| Radio Stations [Member] | |||||
| Goodwill [Line Items] | |||||
| Acquisitions | 80 | 0 | |||
| Digital Media [Member] | |||||
| Goodwill [Line Items] | |||||
| Acquisitions | $ 1,181 | $ 226 | |||
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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Definition Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Definition Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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