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Equity - Non-controlling interests financial information (Details) |  | 12 Months Ended
--- | --- | ---
Nov. 05, 2009 USD ($) | Dec. 31, 2018 CAD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
CONSOLIDATED STATEMENT OF FINANCIAL POSITION |  |  |  |  |  |  |
Non-current assets |  |  | $ 1,241,238,000 | $ 1,308,966,000 |  |  |
Current assets |  |  | 882,579,000 | 691,291,000 |  |  |
Non-current liabilities |  |  | 740,368,000 | 612,303,000 |  |  |
Current liabilities |  |  | 499,077,000 | 450,196,000 |  |  |
CONSOLIDATED INCOME STATEMENT |  |  |  |  |  |  |
Sales |  |  | 2,274,038,000 | 1,741,693,000 | [1] | $ 1,576,037,000 | [1]
Operating profit |  |  | 116,754,000 | 39,697,000 | [1] | (373,080,000) | [1]
Profit before taxes |  |  | 48,808,000 | (20,643,000) | [1] | (405,308,000) | [1]
Net profit (loss) |  |  | 24,573,000 | (5,822,000) | [1] | (358,613,000) | [1]
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Cash flows from operating activities |  |  | 73,777,000 | 150,375,000 |  | 121,169,000 |
Cash flows from investing activities |  |  | (85,875,000) | (74,818,000) |  | (84,281,000) |
Cash flows from financing activities |  |  | 53,303,000 | (113,397,000) |  | 49,917,000 |
Exchange differences on cash and cash equivalents in foreign currencies |  |  | (9,030,000) | 25,330,000 |  | (6,489,000) |
Beginning balance of cash and cash equivalents |  |  | 184,472,000 | 196,982,000 |  | 116,666,000 |
Ending balance of cash and cash equivalents |  |  | 216,647,000 | 184,472,000 |  | 196,982,000 |
Non-controlling interests |  |  | 116,145,000 | 121,734,000 |  |  |
WVA Manufacturing, LLC |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Additional cost per operating agreement | $ 100 |  |  |  |  |  |
WVA Manufacturing, LLC | Globe Specialty Metals Inc |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Non-controlling interests |  |  | 77,343,000 | 80,868,000 |  |  |
Production output sold (as a percentage) | 51.00% |  |  |  |  |  |
WVA Manufacturing, LLC | Globe Specialty Metals Inc | Noncontrolling interests |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF FINANCIAL POSITION |  |  |  |  |  |  |
Non-current assets |  |  | 84,864,000 | 88,532,000 |  |  |
Current assets |  |  | 59,957,000 | 45,269,000 |  |  |
Non-current liabilities |  |  | 14,677,000 | 14,678,000 |  |  |
Current liabilities |  |  | 38,060,000 | 36,359,000 |  |  |
CONSOLIDATED INCOME STATEMENT |  |  |  |  |  |  |
Sales |  |  | 168,041,000 | 161,014,000 |  |  |
Operating profit |  |  | 6,319,000 | 5,947,000 |  |  |
Profit before taxes |  |  | 6,319,000 | 5,947,000 |  |  |
Net profit (loss) |  |  | (6,458,000) | 14,678,000 |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Cash flows from operating activities |  |  | 10,025,000 | 16,017,000 |  |  |
Cash flows from investing activities |  |  | (3,830,000) | (2,193,000) |  |  |
Cash flows from financing activities |  |  |  | (15,000,000) |  |  |
Beginning balance of cash and cash equivalents |  |  | 340,000 | 1,516,000 |  |  |
Ending balance of cash and cash equivalents |  |  | 6,535,000 | 340,000 |  | 1,516,000 |
WVA Manufacturing, LLC | Dow Corning Corporation [Member] |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Production output sold (as a percentage) | 49.00% |  |  |  |  |  |
WVA Manufacturing, LLC | Dow Corning Corporation [Member] | Globe Specialty Metals Inc |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Membership interest sold (as a percentage) | 49.00% |  |  |  |  |  |
Quebec Silicon Limited Partnership [Member] |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Additional cost per operating agreement |  | $ 31 |  |  |  |  |
Quebec Silicon Limited Partnership [Member] | Globe Specialty Metals Inc |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Non-controlling interests |  |  | $ 44,796,000 | 46,830,000 |  |  |
Production output sold (as a percentage) |  | 51.00% | 51.00% |  |  |  |
Quebec Silicon Limited Partnership [Member] | Globe Specialty Metals Inc | Noncontrolling interests |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF FINANCIAL POSITION |  |  |  |  |  |  |
Non-current assets |  |  | $ 62,725,000 | 68,521,000 |  |  |
Current assets |  |  | 42,125,000 | 33,076,000 |  |  |
Non-current liabilities |  |  | 15,406,000 | 14,213,000 |  |  |
Current liabilities |  |  | 24,356,000 | 18,346,000 |  |  |
CONSOLIDATED INCOME STATEMENT |  |  |  |  |  |  |
Sales |  |  | 108,764,000 | 97,697,000 |  |  |
Operating profit |  |  | 2,284,000 | 467,000 |  |  |
Profit before taxes |  |  | 979,000 | 122,000 |  |  |
Net profit (loss) |  |  | 478,000 | 42,000 |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Cash flows from operating activities |  |  | 4,317,000 | 7,076,000 |  |  |
Cash flows from investing activities |  |  | (4,980,000) | (5,422,000) |  |  |
Cash flows from financing activities |  |  |  | (2,000) |  |  |
Exchange differences on cash and cash equivalents in foreign currencies |  |  | (32,000) | 68,000 |  |  |
Beginning balance of cash and cash equivalents |  |  | 2,462,000 | 742,000 |  |  |
Ending balance of cash and cash equivalents |  |  | $ 1,767,000 | $ 2,462,000 |  | $ 742,000 |
Quebec Silicon Limited Partnership [Member] | Dow Corning Corporation [Member] |  |  |  |  |  |  |
CONSOLIDATED STATEMENT OF CASH FLOWS |  |  |  |  |  |  |
Production output sold (as a percentage) |  | 49.00% | 49.00% |  |  |  |
[1] | The amounts for 2016 have been re-presented to show the results of the Spanish energy business within profit (loss) from continuing operations, as described in Note 1 to the consolidated financial statements.

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