v3.10.0.1
Segment Information - Summary of Non-current Asset by Geographic Area (Details) - EUR (€)
€ in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 29, 2017
Dec. 31, 2016
Disclosure Of Operating Segments [Line Items]        
Non-current assets € 2,090 € 1,209    
Property and Equipment        
Disclosure Of Operating Segments [Line Items]        
Non-current assets 197   € 73 € 85
Property and Equipment | Sweden        
Disclosure Of Operating Segments [Line Items]        
Non-current assets 29   32 12
Property and Equipment | United States        
Disclosure Of Operating Segments [Line Items]        
Non-current assets 142   28 50
Property and Equipment | United Kingdom        
Disclosure Of Operating Segments [Line Items]        
Non-current assets 19   6 19
Property and Equipment | Other Countries        
Disclosure Of Operating Segments [Line Items]        
Non-current assets € 7   € 7 € 4