The percentage of common stock and preferred stock of the company owned by a related party.

No definition available.

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- Definition

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.4)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Summary of significant accounting policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Glencore beneficial ownership	42.90%
Glencore economic ownership	47.40%
Allowance for doubtful accounts receivable	$ 1,000	$ 1,000
Minimum [Member] \| Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Minimum [Member] \| Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Minimum [Member] \| Technology and Software [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years
Maximum [Member] \| Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Useful life	45 years
Maximum [Member] \| Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Useful life	35 years
Maximum [Member] \| Technology and Software [Member]
Property, Plant and Equipment [Line Items]
Useful life	7 years
Baise Haohi Carbon Co Ltd [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage, equity method	40.00%