| Goodwill - Carrying Value and Fair Value of Goodwill (Detail) $ in Thousands | 12 Months Ended | 
|---|---|
| Dec. 31, 2021  USD ($)  Accounting | |
| Greater Than11% to 20% [Member] | Radio Clusters [Member] | |
| Carrying Amounts And Fair Values Of Financial Instruments [Line Items] | |
| Number of accounting units | Accounting | 1 | 
| Carrying value including goodwill | $ | $ 8,539 | 
| Greater Than 51% [Member] | Digital Media [Member] | |
| Carrying Amounts And Fair Values Of Financial Instruments [Line Items] | |
| Number of accounting units | Accounting | 1 | 
| Carrying value including goodwill | $ | $ 26,671 | 
| Greater Than 51% [Member] | Publishing [Member] | |
| Carrying Amounts And Fair Values Of Financial Instruments [Line Items] | |
| Number of accounting units | Accounting | 1 | 
| Carrying value including goodwill | $ | $ 1,854 | 
| X | ||||||||||
| 
- Definition Carrying Amounts And Fair Values Of Financial Instruments. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Excess of estimated undiscounted cash flows over carrying value. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Goodwill Impairment Test Number Of Reporting Units. No definition available. 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Details 
 |