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Property, plant and equipment - Owned Assets (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | $ 2,940,777 |
Value at end of period | 3,052,060 | $ 2,940,777
Buildings, plant installations and machinery |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 2,572,455 |
Value at end of period | 2,448,736 | 2,572,455
Plants under construction |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 155,871 |
Value at end of period | 386,905 | 155,871
Ocean going vessels |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 176,499 |
Value at end of period | 182,173 | 176,499
Other |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 35,952 |
Value at end of period | 34,246 | 35,952
Cost |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 5,299,801 | 5,070,619
Additions | 370,136 | 330,636
Disposals and other | 55,139 | 101,454
Transfers |  | 0
Value at end of period | 5,614,798 | 5,299,801
Cost | Buildings, plant installations and machinery |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 4,787,515 | 4,698,142
Additions | 116,850 | 150,570
Disposals and other | 42,453 | 61,197
Transfers |  | 0
Value at end of period | 4,861,912 | 4,787,515
Cost | Plants under construction |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 155,871 | 0
Additions | 231,034 | 118,249
Disposals and other | 0 | 0
Transfers |  | 37,622
Value at end of period | 386,905 | 155,871
Cost | Plants under construction | Geismar 3 Facility |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Transfers |  | 19,000
Cost | Ocean going vessels |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 201,947 | 183,419
Additions | 20,838 | 57,479
Disposals and other | 12,686 | 38,951
Transfers |  | 0
Value at end of period | 210,099 | 201,947
Cost | Other |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 154,468 | 189,058
Additions | 1,414 | 4,338
Disposals and other | 0 | 1,306
Transfers |  | (37,622)
Value at end of period | 155,882 | 154,468
Accumulated depreciation |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | (2,359,024) | (2,213,353)
Disposals and other | (39,688) | (96,386)
Depreciation | 243,402 | 242,057
Value at end of period | (2,562,738) | (2,359,024)
Accumulated depreciation | Buildings, plant installations and machinery |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | (2,215,060) | (2,047,735)
Disposals and other | (31,058) | (63,169)
Depreciation | 229,174 | 230,494
Value at end of period | (2,413,176) | (2,215,060)
Accumulated depreciation | Plants under construction |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | 0 | 0
Disposals and other | 0 | 0
Depreciation | 0 | 0
Value at end of period | 0 | 0
Accumulated depreciation | Ocean going vessels |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | (25,448) | (48,426)
Disposals and other | (8,601) | (31,620)
Depreciation | 11,079 | 8,642
Value at end of period | (27,926) | (25,448)
Accumulated depreciation | Other |  |
Reconciliation of changes in property, plant and equipment [abstract] |  |
Value at beginning of period | (118,516) | (117,192)
Disposals and other | (29) | (1,597)
Depreciation | 3,149 | 2,921
Value at end of period | $ (121,636) | $ (118,516)

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- Definition The amount of additions to property, plant and equipment other than those acquired through business combinations. [Refer: Business combinations [member]; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_i&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of depreciation of property, plant and equipment. [Refer: Depreciation and amortisation expense; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause vii -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_vii&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 75 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_75_a&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The increase (decrease) in property, plant and equipment resulting from transfers. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 54 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_54_a&doctype=Standard -URIDate 2020-01-01 + Details
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