Debt Instrument, Convertible, Conversion Rate, Principal Amount of Convertible Notes for Shares, Principal Amount

No definition available.

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- Definition

Debt Instrument, Restrictive Covenant, Maximum Borrowing Capacity, Amount

+ References

No definition available.

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- Definition

Debt Instrument, Restrictive Covenant, Maximum Borrowing Capacity, Percentage

+ References

No definition available.

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- Definition

Debt Instrument, Restrictive Covenants, Fixed Charge Coverage Ratio

+ References

No definition available.

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- Definition

Line of Credit Facility, Accounts Receivable Available, Percent

+ References

No definition available.

+ Details

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- Definition

Line of Credit Facility, Commitment Fee Description, Average Daily Usage, Percent

+ References

No definition available.

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- Definition

Line of Credit Facility, Factoring Fee, Percent

+ References

No definition available.

+ Details

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- Definition

Number of Subsidiaries

+ References

No definition available.

+ Details

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- Definition

Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ 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

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Period Type:	instant

- Definition

The effective interest rate during the reporting period.

+ References

+ Details

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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- Definition

Interest paid other than in cash for example by issuing additional debt securities. As a noncash item, it is added to net income when calculating cash provided by or used in operations using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

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Debt - Narrative (Details)		3 Months Ended
Debt - Narrative (Details)	Aug. 31, 2017 USD ($) subsidiary	Mar. 31, 2018 USD ($) $ / shares	Mar. 31, 2018 EUR (€)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Noncash interest paid in kind		$ 2,954,000
Number of subsidiaries \| subsidiary	4
5.00% / 7.00% Second Lien Notes due August 31, 2022
Debt Instrument [Line Items]
Convertible debt		$ 171,720,000		$ 168,767,000
5.00% / 7.00% Second Lien Notes due August 31, 2022 \| Minimum
Debt Instrument [Line Items]
Stated interest rate (as a percent)		5.00%	5.00%
5.00% / 7.00% Second Lien Notes due August 31, 2022 \| Maximum
Debt Instrument [Line Items]
Stated interest rate (as a percent)		7.00%	7.00%
Second Lien Notes
Debt Instrument [Line Items]
Debt conversion price (in dollars per share) \| $ / shares		$ 3.77
A.M. Castle & Co. 2017 Management Incentive Plan \| Second Lien Notes
Debt Instrument [Line Items]
Convertible debt		$ 2,400,000
Convertible Debt \| 5.00% / 7.00% Second Lien Notes due August 31, 2022
Debt Instrument [Line Items]
Aggregate principal amount		$ 164,902,000
Debt term		5 years
Debt conversion price (in dollars per share) \| $ / shares		$ 3.77
Principal amount for conversion price calculation		$ 1.00
Convertible Debt \| 5.00% / 7.00% Second Lien Notes due August 31, 2022 \| Minimum
Debt Instrument [Line Items]
Stated interest rate (as a percent)		5.00%	5.00%
Convertible Debt \| 5.00% / 7.00% Second Lien Notes due August 31, 2022 \| Maximum
Debt Instrument [Line Items]
Stated interest rate (as a percent)		7.00%	7.00%
Line of Credit \| Floating rate New ABL Credit Facility due February 28, 2022
Debt Instrument [Line Items]
Line of credit capacity	$ 125,000,000
Line of credit		$ 112,547,000		$ 101,047,000
Foreign Line of Credit
Debt Instrument [Line Items]
Line of credit capacity \| €			€ 6,500,000
Eligible accounts receivable (as a percent)		100.00%
Factoring fee (as a percent)		0.16%
Line of credit		$ 4,803,000
Foreign Line of Credit \| Euribor
Debt Instrument [Line Items]
Interest rate margin (as a percent)		1.00%
Foreign Line of Credit \| LIBOR
Debt Instrument [Line Items]
Interest rate margin (as a percent)		1.00%
Revolving Credit Facility \| Line of Credit \| Floating rate New ABL Credit Facility due February 28, 2022
Debt Instrument [Line Items]
Line of credit capacity		$ 125,000,000
Commitment fee on unused capacity (as a percent)		0.25%
Average daily revolving facility threshold		50.00%
Interest rate during period (as a percent)		4.25%
Fixed charge ratio		1.0	1.0
Cash liquidity percent (as a percent)		10.00%
Covenant borrowing threshold		$ 9,000,000
Revolving Credit Facility \| Line of Credit \| Floating rate New ABL Credit Facility due February 28, 2022 \| Minimum
Debt Instrument [Line Items]
Commitment fee on unused capacity (as a percent)		0.25%
Revolving Credit Facility \| Line of Credit \| Floating rate New ABL Credit Facility due February 28, 2022 \| Maximum
Debt Instrument [Line Items]
Commitment fee on unused capacity (as a percent)		0.375%