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OPERATING SEGMENT REPORTING - Reportable Operating Segments (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Operating Segment Reporting |  |  |
Revenue | $ 128,822 | $ 67,724 | $ 60,388
Revision of estimates and accretion of reclamation obligations | (3,464) | (2,061) | (595)
Property holding costs | (3,896) | (3,879) | (3,536)
Impairment of mineral property interests and property and equipment |  | (711) |
General and administrative expenses | (23,163) | (18,872) | (12,734)
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization) | (11,865) | (44) | 12,951
Depreciation | 9,169 | 3,378 | 1,169
Interest and other expense | (1,619) | (938) | 835
Revision of estimates and accretion of reclamation obligations | (3,464) | (2,061) | (595)
Impairment of mineral property interests and property and equipment |  | (711) |
Gain on sale of assets | (77) | 11 | 24
Unrealized (loss) gain on derivative instrument | (700) | (200) | 1,400
Foreign currency gain | 3,922 | 694 | 581
Net loss before income and mining taxes | (47,640) | (26,003) | 17,306
Mexico |  |  |
Operating Segment Reporting |  |  |
Property holding costs | (2,264) | (2,131) | (1,642)
Impairment of mineral property interests and property and equipment |  | (711) |
General and administrative expenses | (3,770) | (3,772) | (2,688)
Segment income (loss) | 16,780 | 7,584 | 22,651
Impairment of mineral property interests and property and equipment |  | (711) |
MSC |  |  |
Operating Segment Reporting |  |  |
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization) | (11,865) | (44) | 12,951
Segment income (loss) | (11,865) | (44) | 12,951
Los Azules |  |  |
Operating Segment Reporting |  |  |
Property holding costs | (68) | (56) | (405)
General and administrative expenses | (1,046) | (1,242) | (646)
Segment income (loss) | (7,129) | (9,221) | (2,700)
U.S. |  |  |
Operating Segment Reporting |  |  |
Property holding costs | (1,397) | (1,667) | (1,489)
General and administrative expenses | (6,562) | (1,927) | (228)
Segment income (loss) | (13,103) | (8,818) | (6,382)
Canada |  |  |
Operating Segment Reporting |  |  |
Property holding costs | (167) | (25) |
General and administrative expenses | (665) | (92) |
Segment income (loss) | (15,463) | 330 |
Total Segment |  |  |
Operating Segment Reporting |  |  |
Property holding costs | (3,896) | (3,879) | (3,536)
Impairment of mineral property interests and property and equipment |  | (711) |
General and administrative expenses | (12,043) | (7,033) | (3,562)
Income (loss) on investment in Minera Santa Cruz S.A. (net of amortization) | (11,865) | (44) | 12,951
Segment income (loss) | (30,780) | (10,169) | 26,520
Impairment of mineral property interests and property and equipment |  | (711) |
Corporate & Other |  |  |
Operating Segment Reporting |  |  |
Revision of estimates and accretion of reclamation obligations | (3,464) | (2,061) | (595)
General and administrative expenses | (11,120) | (11,839) | (9,172)
Depreciation | (1,178) | (1,453) | (1,169)
Interest and other expense | (1,619) | (938) |
Revision of estimates and accretion of reclamation obligations | (3,464) | (2,061) | (595)
Interest income and other income |  |  | 835
Gain on sale of assets | (77) | 11 | 24
Loss on sale of marketable securities | (3,324) | 257 | 519
Foreign currency gain | 3,922 | 694 | 581
Net loss before income and mining taxes | (47,640) |  |
Gold and silver sales |  |  |
Operating Segment Reporting |  |  |
Revenue | 128,175 | 67,465 | 60,388
Gold and silver sales | Mexico |  |  |
Operating Segment Reporting |  |  |
Revenue | 66,151 | 55,845 | 60,388
Gold and silver sales | Canada |  |  |
Operating Segment Reporting |  |  |
Revenue | 62,024 | 11,620 |
Gold and silver sales | Total Segment |  |  |
Operating Segment Reporting |  |  |
Revenue | 128,175 | 67,465 | 60,388
Other revenue |  |  |
Operating Segment Reporting |  |  |
Revenue | 647 | 259 |
Other revenue | U.S. |  |  |
Operating Segment Reporting |  |  |
Revenue | 30 |  |
Other revenue | Canada |  |  |
Operating Segment Reporting |  |  |
Revenue | 617 | 259 |
Other revenue | Total Segment |  |  |
Operating Segment Reporting |  |  |
Revenue | 647 | 259 |
Production costs applicable to sales |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (93,329) | (45,180) | (28,133)
Production costs applicable to sales | Mexico |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (37,429) | (35,292) | (28,133)
Production costs applicable to sales | Canada |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (55,900) | (9,888) |
Production costs applicable to sales | Total Segment |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (93,329) | (45,180) | (28,133)
Mine development |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (3,667) | (3,837) | (3,866)
Mine development | Mexico |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (3,667) | (745) | (1,174)
Mine development | U.S. |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold |  | (3,092) | (2,692)
Mine development | Total Segment |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (3,667) | (3,837) | (3,866)
Exploration |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (34,802) | (17,714) | (7,959)
Exploration | Mexico |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (2,241) | (5,610) | (4,100)
Exploration | Los Azules |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (6,015) | (7,923) | (1,649)
Exploration | U.S. |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (5,174) | (2,132) | (1,973)
Exploration | Canada |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | (21,372) | (1,544) |
Exploration | Total Segment |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold | $ (34,802) | (17,209) | (7,722)
Other exploration costs | Corporate & Other |  |  |
Operating Segment Reporting |  |  |
Cost of goods and services sold |  | $ (505) | $ (237)

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