Name:	ifrs-full_DisclosureOfInstrumentsWithPotentialFutureDilutiveEffectNotIncludedInCalculationOfDilutedEarningsPerShareLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Threshold period of specified consecutive trading days within which common stock price must exceed threshold percentage for specified number of trading days to trigger vesting feature.

No definition available.

Name:	shmd_EarnoutSharesToBeVestedThresholdConsecutiveTradingDays
Namespace Prefix:	shmd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Threshold number of specified trading days that common stock price must exceed threshold percentage within a specified consecutive trading period to trigger vesting feature.

No definition available.

Name:	shmd_EarnoutSharesToBeVestedThresholdTradingDays
Namespace Prefix:	shmd_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Period over which grantee's right to exercise earnout shares 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.

No definition available.

Name:	shmd_EarnoutSharesVestingPeriod
Namespace Prefix:	shmd_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Price of a single share of a number of saleable stocks of a company.

No definition available.

Name:	shmd_IfrsSharePrice
Namespace Prefix:	shmd_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

Represents the percentage of earnout shares vested.

No definition available.

Name:	shmd_PercentageOfEarnoutSharesVested
Namespace Prefix:	shmd_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Represents the number of shares issuable under earnout agreement.

No definition available.