XML 83 R67.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Treasury Stock - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Equity, Class of Treasury Stock [Line Items]      
Treasury stock, shares repurchased value $ 72,719,000 $ 110,977,000  
Treasury stock, shares 7,807,000 7,285,000  
Treasury stock, cost $ 658,880,000 $ 586,161,000  
Class A      
Equity, Class of Treasury Stock [Line Items]      
Treasury stock, shares repurchased 0 0  
Treasury stock, shares repurchased value $ 0 $ 0  
Class A | Share Repurchase Program      
Equity, Class of Treasury Stock [Line Items]      
Shares repurchased program expiration date Apr. 29, 2023    
Stock authorized to repurchase by board of directors $ 800,000,000.0    
Treasury stock, shares repurchased 521,843 880,667 0
Shares repurchased, average price per share $ 139.35 $ 126.02  
Treasury stock, shares repurchased value $ 72,700,000 $ 111,000,000.0  
Treasury stock, shares 5,229,457    
Shares repurchased, average price per share $ 101.16    
Treasury stock, cost $ 529,000,000.0    
Stock remaining available for repurchase $ 271,000,000.0