| Total assets | 
                
                
                1,902,532 | 
                2,057,634 | 
                2,135,989 | 
                2,222,591 | 
                2,433,831 | 
                2,813,094 | 
                3,004,459 | 
              
              
                | Current assets | 
                
                534,152 | 
                653,718 | 
                830,136 | 
                953,859 | 
                1,107,379 | 
                1,331,179 | 
                1,206,164 | 
              
              
                | Cash and cash equivalents | 
                
               251,818 | 
               350,523 | 
               562,144 | 
               682,962 | 
               826,227 | 
               958,725 | 
               830,592 | 
              
              
                | Trade accounts receivable, net | 
                
                
                78,881 | 
                92,345 | 
                75,214 | 
                89,279 | 
                84,786 | 
                142,029 | 
                119,412 | 
              
              
                | Other accounts receivable | 
               
                59,311 | 
                57,637 | 
                44,983 | 
                34,103 | 
                31,826 | 
                30,283 | 
                26,208 | 
              
              
                | Due from related parties | 
                
                1,417 | 
                2,526 | 
                2,530 | 
                3,196 | 
                5,700 | 
                2,216 | 
                3,170 | 
              
              
                | Inventories | 
                
                98,215 | 
                102,810 | 
                96,522 | 
                95,692 | 
                108,041 | 
                142,020 | 
                159,662 | 
              
              
                | Urban land | 
                
                33,963 | 
                35,478 | 
                36,216 | 
                35,775 | 
                38,060 | 
                41,447 | 
                52,868 | 
              
              
                | Prepaid expenses | 
               
                10,547 | 
                12,399 | 
                12,527 | 
                12,852 | 
                12,739 | 
                14,029 | 
                14,252 | 
              
              
                |   | 
              
              
                | Non-current assets | 
                
                1,368,380 | 
                1,403,916 | 
                1,305,853 | 
                1,268,732 | 
                1,326,452 | 
                1,481,915 | 
                1,798,295 | 
              
              
                | Investment in associates | 
                
                15,548 | 
                18,313 | 
                19,090 | 
                21,888 | 
                23,050 | 
                30,174 | 
                28,595 | 
              
              
                | Property, machinery and equipment, net | 
                
                1,027,760 | 
                1,015,909 | 
                955,592 | 
                934,110 | 
                1,002,294 | 
                1,147,881 | 
                1,427,591 | 
              
              
                | Long term right of use assets | 
                
                - | 
                40,531 | 
                27,954 | 
                19,803 | 
                21,223 | 
                27,020 | 
                27,590 | 
              
              
                | Goodwill | 
                
                246,884 | 
                240,545 | 
                212,598 | 
                212,591 | 
                212,604 | 
                212,598 | 
                239,653 | 
              
              
                | Intangible assets, net | 
                
                73,251 | 
                68,508 | 
                66,766 | 
                62,751 | 
                57,423 | 
                50,448 | 
                60,960 | 
              
              
                | Other assets | 
               
                4,937 | 
                20,110 | 
                23,853 | 
                17,589 | 
                9,858 | 
                13,754 | 
                13,906 | 
              
              
              
                |   | 
              
              
                | Total liabilities | 
               
                930,316 | 
                983,097 | 
                960,847 | 
                911,609 | 
                1,010,019 | 
                1,048,842 | 
                1,053,790 | 
              
              
                | Short-term liabilities | 
               
                162,223 | 
                206,907 | 
                286,913 | 
                380,179 | 
                289,487 | 
                300,664 | 
                305,005 | 
              
              
              
                | Trade accounts payable | 
                
                83,223 | 
                83,625 | 
                89,079 | 
                111,873 | 
                149,604 | 
                155,278 | 
                160,700 | 
              
              
                | Due to related parties | 
                
                1,204 | 
                1,164 | 
                2,205 | 
                2,702 | 
                2,547 | 
                989 | 
                1,022 | 
              
              
                | Short-term employee benefits | 
                
                27,952 | 
                31,852 | 
                35,639 | 
                39,007 | 
                37,127 | 
                47,580 | 
                42,198 | 
              
              
                | Accrued expenses and taxes other than income taxes | 
               
                42,267 | 
                41,402 | 
                47,477 | 
                34,078 | 
                88,190 | 
                83,621 | 
                88,725 | 
              
              
                | Provisions | 
                
                3,177 | 
                2,651 | 
                2,116 | 
                2,167 | 
                3,009 | 
                3,753 | 
                3,112 | 
              
              
                | Short-term right of use liabilities | 
                
                - | 
                20,788 | 
                18,397 | 
                14,352 | 
                9,010 | 
                9,443 | 
                9,248 | 
              
              
                |   | 
              
              
                | Long-term liabilities | 
                
                768,093 | 
                776,190 | 
                673,934 | 
                531,430 | 
                720,532 | 
                748,178 | 
                748,785 | 
              
              
                | Long-term financial debt | 
                
                645,936 | 
                624,566 | 
                536,851 | 
                363,383 | 
                496,684 | 
                496,986 | 
                497,300 | 
              
              
                | Long-term right of use liabilities | 
                
                - | 
                20,661 | 
                8,114 | 
                2,057 | 
                12,114 | 
                18,419 | 
                19,846 | 
              
              
                | Employee benefits | 
                
                35,536 | 
                45,944 | 
                49,937 | 
                39,830 | 
                31,479 | 
                33,186 | 
                28,541 | 
              
              
                | Provision for environmental restoration | 
               
                21,969 | 
                22,677 | 
                18,921 | 
                23,247 | 
                25,781 | 
                25,797 | 
                24,875 | 
              
              
              
              
                | Deferred income taxes | 
                
                43,786 | 
                50,943 | 
                55,233 | 
                99,814 | 
                152,533 | 
                173,790 | 
                178,223 | 
              
              
                |   | 
              
              
                | Total stockholders' equity | 
               
                972,216 | 
                1,074,537 | 
                1,175,142 | 
                1,310,982 | 
                1,423,812 | 
                1,764,251 | 
                1,950,669 | 
              
              
                | Controlling interest | 
                
                972,184 | 
                1,074,504 | 
                1,174,512 | 
                1,310,351 | 
                1,422,851 | 
                1,763,283 | 
                1,949,998 | 
              
              
                | Capital stock | 
                
                32,068 | 
                32,076 | 
                32,070 | 
                32,070 | 
                32,070 | 
                32,070 | 
                32,070 | 
              
              
                | Additional paid-in capital | 
                
                148,365 | 
                148,365 | 
                148,365 | 
                148,365 | 
                148,365 | 
                148,365 | 
                148,365 | 
              
              
                | Legal reserves | 
                
                22,659 | 
                22,659 | 
                22,659 | 
                22,659 | 
                22,659 | 
                22,659 | 
                22,659 | 
              
              
                | Retained earnings | 
               
                986,796 | 
                1,040,717 | 
                1,138,394 | 
                1,251,028 | 
                1,359,143 | 
                1,463,341 | 
                1,729,083 | 
              
              
                | Consolidated net income | 
                
                65,037 | 
                116,733 | 
                129,706 | 
                151,852 | 
                140,258 | 
                295,462 | 
                323,915 | 
              
              
                | Other items of comprehensive income | 
                
                (282,741) | 
                (286,046) | 
                (296,682) | 
                (295,623) | 
                (279,644) | 
                (198,614) | 
                (306,094) | 
              
              
                |  Non-controlling interest | 
                
                32 | 
                33 | 
                630 | 
                631 | 
                961 | 
                968 | 
                671 | 
              
              
                |   | 
              
              
                | 
                  Total liabilities and equity
                 | 
                
                1,902,532 | 
                2,057,634 | 
                2,135,989 | 
                2,222,591 | 
                2,433,831 | 
                2,813,093 | 
                3,004,459 |