Property, Plant and Equipment - Additional Information (Detail) € in Thousands, $ in Thousands	Sep. 30, 2018 USD ($)	Sep. 30, 2018 EUR (€)	Dec. 31, 2017 USD ($)
Property Plant And Equipment [Line Items]
Capital leased assets gross value	$ 3,465		$ 4,082
Capital lease, lease related accumulated amortization	1,023		$ 1,101
Union Electric Steel UK Limited [Member]
Property Plant And Equipment [Line Items]
Land and buildings held as collateral	$ 2,733	€ 2,098

The cost of land and buildings as of the reporting date that are held as collateral for outstanding obligations as of the reporting date.

No definition available.

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Amount before accumulated depreciation of leased physical assets used in the normal conduct of business to produce goods and services.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=84164758&loc=d3e45014-112735

+ Details

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- Definition

The total charge for the use of long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 2)
-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=84164758&loc=d3e45014-112735

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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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- Details

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