Quarterly report pursuant to Section 13 or 15(d)

Other Indefinite-Lived Intangible Assets - Fair Value Measurement Inputs and Valuation Techniques For Mastheads (Detail)

v3.20.2
Other Indefinite-Lived Intangible Assets - Fair Value Measurement Inputs and Valuation Techniques For Mastheads (Detail) - Mastheads [Member]
Sep. 30, 2020
Mar. 31, 2020
Dec. 31, 2019
Measurement Input, Risk-adjusted Discount Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage   10.5 10.0
Measurement Input, Long-term Revenue Growth Rate [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage   3.00 3.00
Minimum [Member] | Measurement Input, Operating Profit Margin [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage (100)   (400)
Maximum [Member] | Measurement Input, Operating Profit Margin [Member]      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Intangible asset measurement input percentage (2,500)   (100)