Debt Instrument, Amortization Percentage

No definition available.

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- Definition

Debt Instrument, Borrowing Base Limitation, Eligible Accounts Receivable, Maximum

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Borrowing Base Limitation, Accordion Feature, Eligible Accounts Receivable and Inventory, Advance rate increase

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Borrowing Base Limitation, Eligible Inventory, Maximum

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Borrowing Base Limitation, Orderly Liquidation Value of Eligible Inventory, Maximum

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Borrowing Base Limitation, Sum of Eligible Cash, Maximum

+ References

No definition available.

+ Details

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Namespace Prefix:	frta_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Collateral Covenant, Percentage of Voting Stock, Maximum

+ References

No definition available.

+ Details

Name:	frta_DebtInstrumentCollateralCovenantPercentageofVotingStockMaximum
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Covenant, Consolidated Earnings Before Income Taxes, Depreciation and Amortization (EBITDA) Ratio

+ References

No definition available.

+ Details

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Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Covenant, Fixed Charge Coverage Ratio

+ References

No definition available.

+ Details

Name:	frta_DebtInstrumentCovenantFixedChargeCoverageRatio
Namespace Prefix:	frta_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Interest Rate, Floor Percentage

+ References

No definition available.

+ Details

Name:	frta_DebtInstrumentInterestRateFloorPercentage
Namespace Prefix:	frta_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Accordion Feature, Increase Limit

+ References

No definition available.

+ Details

Name:	frta_LineofCreditFacilityAccordionFeatureIncreaseLimit
Namespace Prefix:	frta_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Maximum Borrowing Capacity, Accordion Feature, Increase Limit

+ References

No definition available.

+ Details

Name:	frta_LineofCreditFacilityMaximumBorrowingCapacityAccordionFeatureIncreaseLimit
Namespace Prefix:	frta_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

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

- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

+ Details

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

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
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-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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+ Details

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

- Definition

Weighted average interest rate of long-term debt outstanding calculated over time.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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Balance Type:	debit
Period Type:	duration

- Details

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Debt and deferred financing costs - Additional Information (Details) - USD ($)			3 Months Ended
	May 01, 2017	Oct. 25, 2016	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Debt outstanding			$ 1,270,660,000		$ 1,098,303,000
Loss on early extinguishment of debt			50,000	$ 0
Term Loan \| LIBOR
Debt Instrument [Line Items]
Margin rate	3.00%
Revolving Line of Credit \| Revolver
Debt Instrument [Line Items]
Debt outstanding			178,711,000		0
Revolving Line of Credit \| Revolver \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 300,000,000
Line of credit facility, accordion feature, increase limit		100,000,000.0
Line of credit facility, maximum borrowing capacity, accordion feature, increase limit		$ 50,000,000.0
Debt instrument, borrowing base limitation, sum of eligible cash, maximum		100.00%
Debt instrument, borrowing base limitation, eligible accounts receivable, maximum		85.00%
Debt instrument, borrowing base limitation, eligible inventory, maximum		75.00%
Debt instrument, borrowing base limitation, orderly liquidation value of eligible inventory, maximum		85.00%
Debt instrument, borrowing base limitation, eligible accounts receivable and inventory, accordion feature, maximum		2.50%
Outstanding borrowings under revolver			$ 180,000,000		0
Weighted average interest rate on borrowings outstanding			2.06%
Stand-by letters of credit outstanding			$ 15,400,000
Allowable borrowing base			$ 72,100,000
Fixed charge coverage ratio		1.00
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Line of credit, facility fee percentage			0.20%
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Line of credit, facility fee percentage			0.325%
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| Canada
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 20,000,000.0
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| United States
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 280,000,000.0
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| LIBOR or CDOR
Debt Instrument [Line Items]
Debt instrument, collateral covenant, percentage of voting stock, maximum		65.00%
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| LIBOR or CDOR \| Minimum
Debt Instrument [Line Items]
Margin rate		1.25%
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| LIBOR or CDOR \| Maximum
Debt Instrument [Line Items]
Margin rate		1.75%
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| CDOR \| Minimum
Debt Instrument [Line Items]
Margin rate		0.25%
Revolving Line of Credit \| Revolver \| Revolving Credit Facility \| CDOR \| Maximum
Debt Instrument [Line Items]
Margin rate		0.75%
Senior Notes \| Term Loan
Debt Instrument [Line Items]
Debt outstanding		$ 1,100,000,000	$ 1,091,949,000		$ 1,098,303,000
Debt instrument, amortization percentage	0.25%
Weighted average interest rate			4.70%	5.50%
Aggregate principal amount of outstanding debt repurchased			$ 5,000,000
Market value of debt repurchased			4,900,000
Write off of debt issuance costs			100,000
Loss on early extinguishment of debt			$ 100,000
Senior Notes \| Term Loan \| LIBOR
Debt Instrument [Line Items]
Interest rate, floor percentage	1.00%
Senior Notes \| Term Loan \| Base Rate
Debt Instrument [Line Items]
Margin rate	2.00%
Senior Notes \| Term Loan \| LIBOR or CDOR \| Canada
Debt Instrument [Line Items]
Debt instrument, collateral covenant, percentage of voting stock, maximum		65.00%
Senior Notes \| Senior Secured Term Loan
Debt Instrument [Line Items]
Debt outstanding		$ 1,250,000,000
Line of credit facility, accordion feature, increase limit		$ 285,000,000.0
Consolidated EBITDA ratio		1.0