Annual report pursuant to Section 13 and 15(d)

Goodwill - Fair Value Measurement Inputs and Valuation Techniques For Goodwill (Detail)

v3.19.1
Goodwill - Fair Value Measurement Inputs and Valuation Techniques For Goodwill (Detail)
Dec. 31, 2018
Dec. 31, 2017
Measurement Input, Risk-adjusted Discount Rate [Member] | Broadcast Networks Enterprise Valuations [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.100  
Measurement Input, Risk-adjusted Discount Rate [Member] | Radio Clusters [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.090 0.090
Measurement Input, Long-term Revenue Growth Rate [Member] | Broadcast Networks Enterprise Valuations [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.005  
Measurement Input, Long-term Revenue Growth Rate [Member] | Digital Media [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.010  
Measurement Input, Long-term Revenue Growth Rate [Member] | Publishing [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.010 0.019
Measurement Input, Long-term Revenue Growth Rate [Member] | Radio Clusters [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage   0.019
Measurement Input, Discount Rate [Member] | Digital Media [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.100 0.100
Measurement Input, Discount Rate [Member] | Publishing [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.100 0.100
Minimum [Member] | Measurement Input, Operating Profit Margin [Member] | Broadcast Networks Enterprise Valuations [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.148  
Minimum [Member] | Measurement Input, Operating Profit Margin [Member] | Digital Media [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.085 0.080
Minimum [Member] | Measurement Input, Operating Profit Margin [Member] | Publishing [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.040 0.050
Minimum [Member] | Measurement Input, Operating Profit Margin [Member] | Radio Clusters [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage (0.041) (0.078)
Minimum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member] | Digital Media [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage   0.019
Minimum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member] | Radio Clusters [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.005  
Maximum [Member] | Measurement Input, Operating Profit Margin [Member] | Broadcast Networks Enterprise Valuations [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.157  
Maximum [Member] | Measurement Input, Operating Profit Margin [Member] | Digital Media [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.172 0.360
Maximum [Member] | Measurement Input, Operating Profit Margin [Member] | Publishing [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.050 0.055
Maximum [Member] | Measurement Input, Operating Profit Margin [Member] | Radio Clusters [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.451 0.362
Maximum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member] | Digital Media [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage   0.020
Maximum [Member] | Measurement Input, Long-term Revenue Growth Rate [Member] | Radio Clusters [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.011