XML 144 R137.htm IDEA: XBRL DOCUMENT v3.8.0.1
Intangible assets (Details Textual) - EUR (€)
€ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Intangible exploration and evaluation assets € 995 € 1,092 € 735
Concessions licenses trademarks and similar item 182 255  
Copyrights, patents and other industrial property rights, service and operating rights 240 259  
Intangible assets under development 134 148  
Other intangible assets 140 164  
Goodwill 1,204 1,320  
Increase decrease through other changes intangible assets and goodwill (102) 9  
Intangible Assets With Indefinite Useful Life [Member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Increase decrease through other changes intangible assets and goodwill (93)    
Accumulated impairment [member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Goodwill 2,414 2,524  
Licenses by Versalis SpA [Member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Other intangible assets 37 40  
Mineral Rights Under Concession [Member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Other intangible assets 35 41  
Internally Generated [Member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Copyrights, patents and other industrial property rights, service and operating rights 108 235  
Intangible assets under development 78 89  
Internally Generated [Member] | Eni gas e luce SpA [member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Copyrights, patents and other industrial property rights, service and operating rights 121    
Transmission Rights for Natural Gas [Member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Concessions licenses trademarks and similar item 141 223  
Signature bonus and licenses [Member]      
DisclosureOfIntangibleAssetsExplanatoryLineItems [Line Items]      
Additions Other Than Through Business Combinations Intangible Assets Other Than Goodwill € 91 € 15