Convertible Notes with Warrants (November 2023 Financing), Warrants (Details) - November 2023 Financing [Member]		3 Months Ended
Nov. 21, 2023 USD ($)	Mar. 31, 2024 $ / shares
Warrants [Abstract]
Consecutive trading days		10 days
Daily dollar trading volume of common stock exceeds per day	$ 1,000,000
Proceeds from convertible notes	6,850,000
Transaction costs	525,144
Fair value of warrants	2,219,165
Debt discount	$ 2,744,309
Series A Warrants [Member]
Warrants [Abstract]
Percentage of warrant closing price of common stock exceeds	200.00%
Consecutive trading days		10 days
Daily dollar trading volume of common stock exceeds per day	$ 1,000,000
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants term		5 years
Black-Scholes value (in dollars per share) \| $ / shares		$ 0.55
Series A Warrants [Member] \| Risk-free Interest Rate [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		0.0455
Series A Warrants [Member] \| Dividend Yield [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		0
Series A Warrants [Member] \| Expected Volatility [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		1.0489
Series A Warrants [Member] \| Exercise Price [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		1.18
Series A Warrants [Member] \| Stock Price [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		0.95
Series B Warrants [Member]
Warrants [Abstract]
Percentage of warrant closing price of common stock exceeds	200.00%
Consecutive trading days		10 days
Daily dollar trading volume of common stock exceeds per day	$ 1,000,000
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants term		1 year
Black-Scholes value (in dollars per share) \| $ / shares		$ 0.28
Series B Warrants [Member] \| Risk-free Interest Rate [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		0.0524
Series B Warrants [Member] \| Dividend Yield [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		0
Series B Warrants [Member] \| Expected Volatility [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		1.1384
Series B Warrants [Member] \| Exercise Price [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		1.48
Series B Warrants [Member] \| Stock Price [Member]
Fair Value Method and Black-Scholes Assumptions [Abstract]
Warrants, measurement input		0.95

Black-Scholes value price per share or per unit of warrants.

No definition available.

Name:	femy_ClassOfWarrantOrRightBlackScholesValue
Namespace Prefix:	femy_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The consecutive trading days, in which common stock exceeds the conversion price, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	femy_ConsecutiveTradingDaysCommonStockExceedsTheConversionPrice
Namespace Prefix:	femy_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of daily dollar trading volume of the common stock exceeds per day during the same period and certain equity conditions.

+ References

No definition available.

+ Details

Name:	femy_DailyDollarTradingVolumeOfCommonStockExceedsPerDay
Namespace Prefix:	femy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of warrant has the right to call the exercise, if the closing price of the common stock exceeds.

+ References

No definition available.

+ Details

Name:	femy_PercentageOfWarrantClosingPriceOfCommonStockExceedsPercentage
Namespace Prefix:	femy_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	femy_WarrantsTransactionsAbstract
Namespace Prefix:	femy_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482925/835-30-45-1A

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482949/835-30-55-8

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1D
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1D

+ Details

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

- Definition

Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-28

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 25
-Paragraph 13
-SubTopic 10
-Topic 480
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481766/480-10-25-13

+ Details

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

- References

No definition available.

+ Details

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

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-15

+ Details

Name:	us-gaap_PaymentsOfDebtIssuanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from the issuance of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-14

+ Details

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

- Definition

Value of input used to measure outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_WarrantsAndRightsOutstandingMeasurementInput
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
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
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_WarrantsAndRightsOutstandingTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=femy_November2023FinancingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=femy_SeriesAWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputRiskFreeInterestRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputExpectedDividendRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputPriceVolatilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputExercisePriceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputSharePriceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=femy_SeriesBWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: