| Broadcast Licenses - Additional Information (Detail) | 6 Months Ended | 
|---|---|
| Jun. 30, 2019 | |
| Broadcast Licenses [Member] | |
| Indefinite-lived Intangible Assets [Line Items] | |
| License renewable term | 8 years | 
| X | ||||||||||
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- Definition License renewal term. No definition available. 
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| X | ||||||||||
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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. No definition available. 
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| X | ||||||||||
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- Details 
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