Class Of Warrant Or Right, Percentage Of Oustanding Common Shares

No definition available.

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- Definition

Debt Instrument Covenant For Additional Financing

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt Instrument, Interest Coverage Ratio

+ References

No definition available.

+ Details

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- Definition

Line Of Credit Facility, Limit Availability, Cost Of Eligible Inventory

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Line Of Credit Facility, Limit Availability, Liquidation Value

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Line Of Credit Facility, Limit Availability, Value Of Eligible Accounts

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Payment Demand Amount

+ References

No definition available.

+ Details

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Namespace Prefix:	rail_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Payment Demand Amount, Term

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Face amount or stated value per share of common stock.

+ References

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Net increase or decrease in the carrying amount of the debt instrument for the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

+ Details

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- 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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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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-SubTopic 30
-Section 45
-Paragraph 3
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Discussion of whether the borrowings under the credit facility are secured or unsecured and, if secured, a description of collateral (for example, accounts receivable less than 120 days old, finished goods inventory).

+ References

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+ Details

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Balance Type:	na
Period Type:	duration

- 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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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

+ References

No definition available.

+ Details

Name:	us-gaap_WarrantsAndRightsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=rail_SienaLoanAgreementMember
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Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=rail_MTBankMember
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Data Type:	na
Balance Type:
Period Type:

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Debt Financing and Revolving Credit Facilities (Narrative) (Details) $ / shares in Units, $ in Thousands				6 Months Ended	12 Months Ended
	Jul. 31, 2021 USD ($)	May 14, 2021 USD ($) $ / shares	Nov. 24, 2020 USD ($) $ / shares	Jun. 30, 2021 USD ($) Item $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 18, 2020 USD ($)	Oct. 08, 2020 USD ($)	Aug. 07, 2020 USD ($)
Line of Credit Facility [Line Items]
Common Stock, Par or Stated Value Per Share \| $ / shares			$ 0.01	$ 0.01	$ 0.01
Class Of Warrant Or Right, Percentage Of Oustanding Common Shares			23.00%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights \| shares				5,305,140	5,307,539
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares				$ 0.01	$ 0.01
Warrants and Rights Outstanding				$ 31,406	$ 12,730
Paycheck Protection Program Loan [Member]
Line of Credit Facility [Line Items]
Aggregate principal amount				10,000
Siena Loan Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity				17	9,701
deferred financing costs, gross							$ 1,101
Maximum borrowing capacity				20,000			$ 20,000
Outstanding borrowings				$ 2,613	6,874
Value of eligible accounts				85.00%
Liquidation value				85.00%
Cost of eligible inventory				50.00%
Interest rate				6.26%
Siena Loan Agreement [Member] \| Base Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate				3.00%
Term Loan Credit Agreement [Member]
Line of Credit Facility [Line Items]
deferred financing costs		$ 480	$ 2,872	$ 2,994	$ 2,814
Aggregate principal amount		56,000		$ 40,000
Term				5 years
Additional loan amount		$ 16,000		$ 16,000
Covenant for additional financing	$ 15,000
Additional loan interest rate				14.75%
Debt payment terms		Pursuant to the Amendment, in the event that the Additional Loan is not repaid in full by March 31, 2022, the Company shall issue to the Lender and/or an affiliate of the Lender a warrant (the “Additional Warrant”) to purchase a number of shares of the Company’s common stock, par value $0.01 per share, equal to 5% of the Company’s outstanding common stock on a fully-diluted basis at the time the Additional Warrant is exercised (after giving effect to such issuance).
Warrants outstanding term		10 years
Interest rate				14.00%
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares		$ 0.01
M & T Bank [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Collateral				6,889	6,975
Maximum borrowing capacity				$ 40,000
Outstanding borrowings				$ 10,518	$ 10,105
Payment demand						$ 10,114		$ 5,081
Payment term				5 days
Interest coverage ratio \| Item				1.25
Interest rate				4.18%