Annual report pursuant to Section 13 and 15(d)

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

v3.19.1
Other Indefinite-Lived Intangible Assets - Fair Value Measurement Inputs and Valuation Techniques For Mastheads (Detail) - Mastheads [Member]
Dec. 31, 2018
Dec. 31, 2017
Measurement Input, Risk-adjusted Discount Rate [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.10 0.10
Measurement Input, Long-term Revenue Growth Rate [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage 0.03 0.03
Minimum [Member] | Measurement Input, Operating Profit Margin [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage (0.040) (0.032)
Maximum [Member] | Measurement Input, Operating Profit Margin [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Intangible asset measurement input percentage (0.010) 0.009