v3.10.0.1
Revenue Recognition - Additional Information (Detail) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Contract Liabilities [Abstract]      
Deferred revenue € 258 € 216  
Description of when entity typically satisfies performance obligations over a period up to a year    
Revenue recognition € 210 € 149 € 92