| 
                Total assets
             | 
                        
                3.9B
             | 
                        
                3.8B
             | 
                        
                2.9B
             | 
                        
                1.5B
             | 
                    
                
                        | 
                Current assets
             | 
                        
                1.1B
             | 
                        
                1.3B
             | 
                        
                1.5B
             | 
                        
                212M
             | 
                    
                
                        | 
                Cash
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Cash equivalents
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Cash and cash equivalents
             | 
                        
                762M
             | 
                        
                917M
             | 
                        
                1.2B
             | 
                        
                70M
             | 
                    
                
                        | 
                Other short term investments
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Accounts receivable
             | 
                        
                8M
             | 
                        
                14M
             | 
                        
                7M
             | 
                        
                3M
             | 
                    
                
                        | 
                Other receivables
             | 
                        
                357M
             | 
                        
                304M
             | 
                        
                226M
             | 
                        
                128M
             | 
                    
                
                        | 
                Inventory
             | 
                        
                —
             | 
                        
                —
             | 
                        
                0
             | 
                        
                1M
             | 
                    
                
                        | 
                Prepaid assets
             | 
                        
                —
             | 
                        
                —
             | 
                        
                16M
             | 
                        
                15M
             | 
                    
                
                        | 
                Restricted cash
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Assets held for sale
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Hedging assets
             | 
                        
                3M
             | 
                        
                58M
             | 
                        
                26M
             | 
                        
                6M
             | 
                    
                
                        | 
                Other current assets
             | 
                        
                -2M
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Non current assets
             | 
                        
                2.7B
             | 
                        
                2.5B
             | 
                        
                1.4B
             | 
                        
                1.3B
             | 
                    
                
                        | 
                Properties
             | 
                        
                2.7B
             | 
                        
                2.3B
             | 
                        
                2.2B
             | 
                        
                2.2B
             | 
                    
                
                        | 
                Land and improvements
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Machinery furniture equipment
             | 
                        
                27M
             | 
                        
                23M
             | 
                        
                16M
             | 
                        
                9M
             | 
                    
                
                        | 
                Construction in progress
             | 
                        
                991M
             | 
                        
                1.2B
             | 
                        
                184M
             | 
                        
                145M
             | 
                    
                
                        | 
                Leases
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Accumulated depreciation
             | 
                        
                -1.3B
             | 
                        
                -1.3B
             | 
                        
                -1.2B
             | 
                        
                -1.1B
             | 
                    
                
                        | 
                Goodwill
             | 
                        
                31M
             | 
                        
                30M
             | 
                        
                25M
             | 
                        
                25M
             | 
                    
                
                        | 
                Investment properties
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Financial assets
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Intangible assets
             | 
                        
                31M
             | 
                        
                30M
             | 
                        
                25M
             | 
                        
                25M
             | 
                    
                
                        | 
                Investments and advances
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Other non current assets
             | 
                        
                -1M
             | 
                        
                —
             | 
                        
                1M
             | 
                        
                1M
             | 
                    
                
                        | 
                Total liabilities
             | 
                        
                1.7B
             | 
                        
                1.6B
             | 
                        
                1.3B
             | 
                        
                835M
             | 
                    
                
                        | 
                Current liabilities
             | 
                        
                756M
             | 
                        
                176M
             | 
                        
                258M
             | 
                        
                361M
             | 
                    
                
                        | 
                Accounts payable
             | 
                        
                36M
             | 
                        
                27M
             | 
                        
                49M
             | 
                        
                23M
             | 
                    
                
                        | 
                Accrued expenses
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Short term debt
             | 
                        
                607M
             | 
                        
                59M
             | 
                        
                29M
             | 
                        
                150M
             | 
                    
                
                        | 
                Deferred revenue
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Tax payable
             | 
                        
                1M
             | 
                        
                4M
             | 
                        
                3M
             | 
                        
                3M
             | 
                    
                
                        | 
                Pensions
             | 
                        
                24M
             | 
                        
                30M
             | 
                        
                24M
             | 
                        
                12M
             | 
                    
                
                        | 
                Other current liabilities
             | 
                        
                1M
             | 
                        
                2M
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Non current liabilities
             | 
                        
                918M
             | 
                        
                1.4B
             | 
                        
                1.0B
             | 
                        
                474M
             | 
                    
                
                        | 
                Long term provisions
             | 
                        
                89M
             | 
                        
                90M
             | 
                        
                62M
             | 
                        
                49M
             | 
                    
                
                        | 
                Long term debt
             | 
                        
                646M
             | 
                        
                1.1B
             | 
                        
                980M
             | 
                        
                425M
             | 
                    
                
                        | 
                Provision for risks and charges
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Deferred liabilities
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                0
             | 
                    
                
                        | 
                Derivative product liabilities
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Other non current liabilities
             | 
                        
                183M
             | 
                        
                201M
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Shareholders equity
             | 
                        
                
             | 
                        
                
             | 
                        
                
             | 
                        
                
             | 
                    
                
                        | 
                Common stock
             | 
                        
                4M
             | 
                        
                4M
             | 
                        
                4M
             | 
                        
                3M
             | 
                    
                
                        | 
                Retained earnings
             | 
                        
                525M
             | 
                        
                337M
             | 
                        
                129M
             | 
                        
                -643M
             | 
                    
                
                        | 
                Other shareholders equity
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Total shareholders equity
             | 
                        
                2.2B
             | 
                        
                2.2B
             | 
                        
                1.6B
             | 
                        
                676M
             | 
                    
                
                        | 
                Additional paid in capital
             | 
                        
                1.3B
             | 
                        
                1.5B
             | 
                        
                1.6B
             | 
                        
                1.4B
             | 
                    
                
                        | 
                Treasury stock
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Minority interest
             | 
                        
                314M
             | 
                        
                318M
             | 
                        
                0
             | 
                        
                —
             |