OTHER CURRENT LIABILITIES (Details) - EUR (€) € in Thousands	Jun. 30, 2026	Dec. 31, 2025	Dec. 31, 2024
OTHER CURRENT LIABILITIES.
Personnel related accruals		€ 4,621	€ 2,579
Tax related accruals		992	432
Audit related accruals		1,853	2,400
Production related accruals		2,645	1,596
Liabilities due to reorganization			2,809
Legal and consulting fees		252	3,140
Miscellaneous other current liabilities		5,142	4,557
Total other current liabilities	€ 13,373	€ 15,505	€ 17,513

The amount of current liabilities that the entity does not separately disclose in the same statement or note. [Refer: Current liabilities]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_55&doctype=Standard
-URIDate 2025-03-27

+ Details

Name:	ifrs-full_OtherCurrentLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of current non-financial liabilities that the entity does not separately disclose in the same statement or note. [Refer: Other financial liabilities]

+ References

+ Details

Name:	ifrs-full_OtherCurrentNonfinancialLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of accruals for employee benefits (other than termination benefits) that are expected to be settled wholly within twelve months after the end of the annual reporting period in which the employees render the related services. [Refer: Accruals classified as current]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 78
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78&doctype=Standard
-URIDate 2025-03-27

+ Details

Name:	ifrs-full_ShorttermEmployeeBenefitsAccruals
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of current provision for restructuring. [Refer: Restructuring provision]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 37
-IssueDate 2025-01-01
-Paragraph 70
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=37&code=ifrs-tx-2025-en-r&anchor=para_70&doctype=Standard
-URIDate 2025-03-27

+ Details

Name:	ifrs-full_ShorttermRestructuringProvision
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of accrued audit fees, current.

+ References

No definition available.

+ Details

Name:	shmd_AccruedAuditFeesCurrent
Namespace Prefix:	shmd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of accrued production, current.

+ References

No definition available.

+ Details

Name:	shmd_AccruedProductionCurrent
Namespace Prefix:	shmd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	shmd_DisclosureOfOtherCurrentLiabilitiesAbstract
Namespace Prefix:	shmd_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of current legal and consulting fees payable.

+ References

No definition available.

+ Details

Name:	shmd_LegalAndConsultingFeesPayableCurrent
Namespace Prefix:	shmd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The current amount of tax related accruals.

+ References

No definition available.

+ Details

Name:	shmd_TaxRelatedAccruals
Namespace Prefix:	shmd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant