| 
                Total assets
             | 
                        
                295.9M
             | 
                        
                289.5M
             | 
                        
                351.4M
             | 
                        
                349.8M
             | 
                    
                
                        | 
                Current assets
             | 
                        
                44.2M
             | 
                        
                45.2M
             | 
                        
                103.0M
             | 
                        
                101.9M
             | 
                    
                
                        | 
                Cash
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Cash equivalents
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Cash and cash equivalents
             | 
                        
                8.2M
             | 
                        
                11.5M
             | 
                        
                69.2M
             | 
                        
                69.2M
             | 
                    
                
                        | 
                Other short term investments
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Accounts receivable
             | 
                        
                —
             | 
                        
                —
             | 
                        
                726.9K
             | 
                        
                —
             | 
                    
                
                        | 
                Other receivables
             | 
                        
                —
             | 
                        
                —
             | 
                        
                32.4M
             | 
                        
                32.8M
             | 
                    
                
                        | 
                Inventory
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Prepaid assets
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Restricted cash
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Assets held for sale
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Hedging assets
             | 
                        
                —
             | 
                        
                —
             | 
                        
                272.6K
             | 
                        
                —
             | 
                    
                
                        | 
                Other current assets
             | 
                        
                36.0M
             | 
                        
                33.6M
             | 
                        
                -181.7K
             | 
                        
                -90.9K
             | 
                    
                
                        | 
                Non current assets
             | 
                        
                251.8M
             | 
                        
                244.3M
             | 
                        
                248.3M
             | 
                        
                247.9M
             | 
                    
                
                        | 
                Properties
             | 
                        
                220.8M
             | 
                        
                —
             | 
                        
                247.9M
             | 
                        
                217.2M
             | 
                    
                
                        | 
                Land and improvements
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Machinery furniture equipment
             | 
                        
                —
             | 
                        
                —
             | 
                        
                2.5M
             | 
                        
                —
             | 
                    
                
                        | 
                Construction in progress
             | 
                        
                —
             | 
                        
                —
             | 
                        
                90.0M
             | 
                        
                —
             | 
                    
                
                        | 
                Leases
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Accumulated depreciation
             | 
                        
                —
             | 
                        
                —
             | 
                        
                -121.5M
             | 
                        
                —
             | 
                    
                
                        | 
                Goodwill
             | 
                        
                2.8M
             | 
                        
                2.8M
             | 
                        
                2.8M
             | 
                        
                2.8M
             | 
                    
                
                        | 
                Investment properties
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Financial assets
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Intangible assets
             | 
                        
                —
             | 
                        
                —
             | 
                        
                2.8M
             | 
                        
                —
             | 
                    
                
                        | 
                Investments and advances
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Other non current assets
             | 
                        
                —
             | 
                        
                —
             | 
                        
                -90.9K
             | 
                        
                —
             | 
                    
                
                        | 
                Total liabilities
             | 
                        
                103.9M
             | 
                        
                95.6M
             | 
                        
                152.1M
             | 
                        
                153.1M
             | 
                    
                
                        | 
                Current liabilities
             | 
                        
                37.6M
             | 
                        
                24.0M
             | 
                        
                68.7M
             | 
                        
                68.5M
             | 
                    
                
                        | 
                Accounts payable
             | 
                        
                —
             | 
                        
                —
             | 
                        
                3.3M
             | 
                        
                —
             | 
                    
                
                        | 
                Accrued expenses
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Short term debt
             | 
                        
                14.4M
             | 
                        
                5.7M
             | 
                        
                55.2M
             | 
                        
                56.7M
             | 
                    
                
                        | 
                Deferred revenue
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Tax payable
             | 
                        
                —
             | 
                        
                —
             | 
                        
                90.9K
             | 
                        
                —
             | 
                    
                
                        | 
                Pensions
             | 
                        
                —
             | 
                        
                —
             | 
                        
                2.2M
             | 
                        
                —
             | 
                    
                
                        | 
                Other current liabilities
             | 
                        
                23.2M
             | 
                        
                18.3M
             | 
                        
                90.9K
             | 
                        
                11.8M
             | 
                    
                
                        | 
                Non current liabilities
             | 
                        
                66.3M
             | 
                        
                71.6M
             | 
                        
                83.4M
             | 
                        
                84.6M
             | 
                    
                
                        | 
                Long term provisions
             | 
                        
                8.1M
             | 
                        
                8.1M
             | 
                        
                8.1M
             | 
                        
                8.1M
             | 
                    
                
                        | 
                Long term debt
             | 
                        
                51.3M
             | 
                        
                52.8M
             | 
                        
                58.7M
             | 
                        
                57.9M
             | 
                    
                
                        | 
                Provision for risks and charges
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Deferred liabilities
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Derivative product liabilities
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Other non current liabilities
             | 
                        
                6.9M
             | 
                        
                10.7M
             | 
                        
                16.6M
             | 
                        
                18.6M
             | 
                    
                
                        | 
                Shareholders equity
             | 
                        
                
             | 
                        
                
             | 
                        
                
             | 
                        
                
             | 
                    
                
                        | 
                Common stock
             | 
                        
                —
             | 
                        
                —
             | 
                        
                363.4K
             | 
                        
                —
             | 
                    
                
                        | 
                Retained earnings
             | 
                        
                —
             | 
                        
                —
             | 
                        
                47.7M
             | 
                        
                —
             | 
                    
                
                        | 
                Other shareholders equity
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Total shareholders equity
             | 
                        
                191.9M
             | 
                        
                193.8M
             | 
                        
                199.3M
             | 
                        
                196.7M
             | 
                    
                
                        | 
                Additional paid in capital
             | 
                        
                —
             | 
                        
                —
             | 
                        
                121.6M
             | 
                        
                —
             | 
                    
                
                        | 
                Treasury stock
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                        
                —
             | 
                    
                
                        | 
                Minority interest
             | 
                        
                29.2M
             | 
                        
                26.5M
             | 
                        
                28.5M
             | 
                        
                28.3M
             |