Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved under plan	4,500,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of stock option or unit granted	10 years
Stock option vesting period option	3 years
Percentage of stock options to become vested and exercisable	100.00%
Weighted-average grant-date fair value	$ 6.47	$ 8.91	$ 7.29
Recognized stock-based compensation expense	$ 1,801	$ 1,528	$ 1,560
Unearned compensation cost related to the unvested portion of all stock-based awards	$ 1,469	$ 606	$ 587
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of stock option or unit granted	3 years
Number of share based compensation units granted	344,224
Maximum payout percentage	200.00%
Weighted-average grant-date fair value	$ 17.61	$ 22.92	$ 14.89
Vesting period	3 years
Recognized stock-based compensation expense	$ 3,607	$ 4,152	$ 6,772
Unearned compensation cost related to the unvested portion of all stock-based awards	$ 2,730	$ 3,599	$ 3,726
Performance Share Units Associated With 2019 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares outstanding	200,000
Performance Share Units Associated With 2018 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares outstanding	100,000
Restricted Stock Units[Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share based compensation units granted	200,000	100,000	200,000
Vesting period	3 years
Recognized stock-based compensation expense	$ 1,700	$ 2,200	$ 1,500
Unearned compensation cost related to the unvested portion of all stock-based awards	$ 2,800	$ 2,800	$ 2,400
Director's Deferred Compensation [Member] \| Common Shares in Treasury [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock held in rabbi trust	100,000	100,000
Value of common stock held in rabbi trust	$ 1,600	$ 1,200

Common Stock Issued Employee Stock Trust Shares

No definition available.

Name:	foe_CommonStockIssuedEmployeeStockTrustShares
Namespace Prefix:	foe_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum Payout Percentage

+ References

No definition available.

+ Details

Name:	foe_MaximumPayoutPercentage
Namespace Prefix:	foe_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share Based Compensation Arrangement By Share Based Payment Award Percentage Vested Upon Death Retirement Or Change In Control

+ References

No definition available.

+ Details

Name:	foe_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageVestedUponDeathRetirementOrChangeInControl
Namespace Prefix:	foe_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share Based Compensation Arrangement By Share Based Payment Award Terms Of Award 1

+ References

No definition available.

+ Details

Name:	foe_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward1
Namespace Prefix:	foe_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Option Vesting Period Option One

+ References

No definition available.

+ Details

Name:	foe_StockOptionVestingPeriodOptionOne
Namespace Prefix:	foe_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Value of common stock issued to a trust (for example, a 'rabbi trust') set up specifically to accumulate stock for the sole purpose of distribution to participating employees. This trust does not allow employees to immediately or after a holding period diversify into nonemployer securities. The deferred compensation plan for which this trust is set up must be settled by the delivery of a fixed number of shares of employer stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 25
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=75028277&loc=d3e19833-108362

+ Details

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

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

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

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares issued which are neither cancelled nor held in the treasury.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=foe_PerformanceSharesUnits2019GrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=foe_PerformanceSharesUnits2018GrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=foe_DirectorsDeferredCompensationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_TreasuryStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: