Impairment of FCC Broadcasting Licenses - Summary of Key Assumptions Used in Impairment Assessment Using Significant Unobservable Inputs (Details) - Level 3 - Fair Value, Measurements, Nonrecurring - Discounted Cash Flow Methodology	Mar. 31, 2020
Radio FCC Licenses | Discount Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	10.5
Radio FCC Licenses | Long-term Revenue Growth Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	0.1
Radio FCC Licenses | Long-term Revenue Growth Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	0.8
Radio FCC Licenses | Mature Market Share | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	3.0
Radio FCC Licenses | Mature Market Share | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	18.0
Radio FCC Licenses | Mature Operating Profit Margin | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	28.0
Radio FCC Licenses | Mature Operating Profit Margin | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	33.6
Television FCC Licenses | Discount Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	11.0
Television FCC Licenses | Long-term Revenue Growth Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	1.0
Television FCC Licenses | Mature Market Share | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	2.0
Television FCC Licenses | Mature Market Share | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	2.9
Television FCC Licenses | Mature Operating Profit Margin
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Alternative investment, measurement input	24.0