| | Balance as of January 1, 2016 | | Additions | | Disposals | | Sales | | Reclassifications of assets held for sale | | Reclassifications and transfers | | Balance as of December 31, 2016 | | Additions | | Disposals | | Sales | | Reclassifications and transfers | | Balance as of December 31, 2017 | | ||||||||||||
| | US$(000) | | US$(000) | | US$(000) | | US$(000) | | | | US$(000) | | US$(000) | | US$(000) | | US$(000) | | US$(000) | | US$(000) | | US$(000) | | ||||||||||||
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Cost | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Lands | | | 22,454 | | | 162 | | | - | | | (6) | | | 78 | | | 270 | | | 22,958 | | | - | | | - | | | - | | | (268) | | | 22,690 | |
Mining concessions | | | 198,009 | | | - | | | - | | | - | | | - | | | - | | | 198,009 | | | 2 | | | - | | | (15,000) | | | (31,138) | | | 151,873 | |
Development costs | | | 541,763 | | | 82,865 | | | - | | | - | | | 31,192 | | | (3,428) | | | 652,392 | | | 69,335 | | | - | | | (10,107) | | | 431 | | | 712,051 | |
Buildings, constructions and other | | | 1,018,956 | | | 581 | | | - | | | (20) | | | 10,458 | | | 79,192 | | | 1,109,167 | | | 835 | | | (387) | | | (28,751) | | | 198,387 | | | 1,279,251 | |
Machinery and equipment | | | 827,225 | | | 46,152 | | | (6,569) | | | (2,844) | | | 9,425 | | | 112,643 | | | 986,032 | | | 2,579 | | | (3,749) | | | (50,097) | | | (5,742) | | | 929,023 | |
Transportation units | | | 10,649 | | | 174 | | | (341) | | | (396) | | | 357 | | | (27) | | | 10,416 | | | 11 | | | (190) | | | (1,079) | | | 788 | | | 9,946 | |
Furniture and fixtures | | | 13,429 | | | 89 | | | (61) | | | (88) | | | 359 | | | 319 | | | 14,047 | | | 31 | | | (157) | | | (487) | | | 468 | | | 13,902 | |
Units in transit | | | 26,291 | | | 15,797 | | | - | | | - | | | - | | | (12,037) | | | 30,051 | | | 2,822 | | | - | | | - | | | (28,124) | | | 4,749 | |
Work in progress | | | 68,123 | | | 210,915 | | | (352) | | | - | | | 1,037 | | | (173,935) | | | 105,788 | | | 173,333 | | | - | | | (190) | | | (177,809) | | | 101,122 | |
Stripping activity asset (e) | | | 106,838 | | | 17,631 | | | - | | | - | | | - | | | (2) | | | 124,467 | | | 18,282 | | | (13,573) | | | - | | | 1,271 | | | 130,447 | |
Mine closure costs | | | 187,603 | | | 34,532 | | | - | | | - | | | 25,754 | | | - | | | 247,889 | | | 10,594 | | | - | | | (17,195) | | | - | | | 241,288 | |
| | | 3,021,340 | | | 408,898 | | | (7,323) | | | (3,354) | | | 78,660 | | | 2,995 | | | 3,501,216 | | | 277,824 | | | (18,056) | | | (122,906) | | | (41,736) | | | 3,596,342 | |
Accumulated depreciation and amortization: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Mining concessions | | | 77,450 | | | 16 | | | - | | | - | | | - | | | - | | | 77,466 | | | 8 | | | - | | | (13,845) | | | (23,390) | | | 40,239 | |
Development costs | | | 199,211 | | | 18,225 | | | - | | | - | | | 25,596 | | | (1,396) | | | 241,636 | | | 30,886 | | | - | | | (7,910) | | | (241) | | | 264,371 | |
Buildings, construction and other | | | 381,441 | | | 65,050 | | | - | | | (9) | | | 8,598 | | | 598 | | | 455,678 | | | 73,314 | | | (115) | | | (28,208) | | | 6,168 | | | 506,837 | |
Machinery and equipment | | | 475,941 | | | 81,753 | | | (5,378) | | | (827) | | | 6,640 | | | (68) | | | 558,061 | | | 74,744 | | | (2,662) | | | (41,595) | | | (6,099) | | | 582,449 | |
Transportation units | | | 7,932 | | | 1,103 | | | (250) | | | (365) | | | 358 | | | 14 | | | 8,792 | | | 837 | | | (114) | | | (1,057) | | | (68) | | | 8,390 | |
Furniture and fixtures | | | 7,577 | | | 1,156 | | | (60) | | | (22) | | | 319 | | | 202 | | | 9,172 | | | 1,109 | | | (152) | | | (236) | | | (13) | | | 9,880 | |
Stripping activity asset | | | 12,916 | | | 5,813 | | | - | | | - | | | - | | | - | | | 18,729 | | | 16,343 | | | - | | | - | | | 6,623 | | | 41,695 | |
Mine closure costs | | | 99,993 | | | 22,417 | | | - | | | - | | | 19,335 | | | (470) | | | 141,275 | | | 25,254 | | | - | | | (8,408) | | | - | | | 158,121 | |
| | | 1,262,461 | | | 195,533 | | | (5,688) | | | (1,223) | | | 60,846 | | | (1,120) | | | 1,510,809 | | | 222,495 | | | (3,043) | | | (101,259) | | | (17,020) | | | 1,611,982 | |
Provision for impairment of long-lived assets: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Mine closure costs | | | 4,080 | | | - | | | - | | | - | | | 6,910 | | | - | | | 10,990 | | | 17,916 | | | - | | | (8,785) | | | - | | | 20,121 | |
Development costs | | | 3,803 | | | - | | | - | | | - | | | 5,684 | | | - | | | 9,487 | | | 2,864 | | | - | | | (2,198) | | | - | | | 10,153 | |
Mining concessions, development costs, property, plant and other | | | 3,372 | | | - | | | - | | | - | | | 6,533 | | | - | | | 9,905 | | | 840 | | | - | | | (6,214) | | | - | | | 4,531 | |
| | | 11,255 | | | - | | | - | | | - | | | 19,127 | | | - | | | 30,382 | | | 21,620 | | | - | | | (17,197) | | | - | | | 34,805 | |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Net cost | | | 1,747,624 | | | | | | | | | | | | | | | | | | 1,960,025 | | | | | | | | | | | | | | | 1,949,555 | |