XML 164 R124.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Tax Expense - Additional Information (Detail) - 12 months ended Dec. 31, 2017
€ in Millions
EUR (€)
USD ($)
Disclosure of reconciliation of effective and applicable income tax expenses [line items]    
Deferred tax assets | $   $ 0
Amount of losses carried forward € 369  
Parent [member]    
Disclosure of reconciliation of effective and applicable income tax expenses [line items]    
Amount of losses carried forward € 334  
French (Member)    
Disclosure of reconciliation of effective and applicable income tax expenses [line items]    
Effective income tax rate 33.33%