Annual report pursuant to Section 13 and 15(d)

Broadcast Licenses - Fair Value Measurement Inputs and Valuation Techniques for Broadcast Licenses (Detail)

v3.20.1
Broadcast Licenses - Fair Value Measurement Inputs and Valuation Techniques for Broadcast Licenses (Detail) - Broadcast Licenses [Member]
Dec. 31, 2019
Sep. 30, 2019
Dec. 31, 2018
Measurement Input, Risk-adjusted Discount Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage 0.090 0.090 0.090
Minimum [Member] | Measurement Input, Operating Profit Margin [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage 0.040 0.043 0.044
Minimum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage 0.007 0.007 0.005
Maximum [Member] | Measurement Input, Operating Profit Margin [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage 0.338 0.307 0.345
Maximum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage 0.011 0.011 0.012