Summary of Significant Accounting Policies, Leases (Details)	12 Months Ended
Dec. 31, 2022
Leases [Abstract]
Minimum term to record operating leases as right-to-use assets and operating lease liabilities	1 year
Minimum term to record finance leases as right-to-use assets and finance lease liabilities	1 year

Minimum term to record operating leases as right-to-use assets and operating lease liabilities, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

No definition available.

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