Name:	grfs_DebtCovenantLeverageRatio
Namespace Prefix:	grfs_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

Represents the decrease in borrowings through repayments in credit facility.

No definition available.

Name:	grfs_DecreaseInBorrowingsThroughRepayments
Namespace Prefix:	grfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

No definition available.

Name:	grfs_IFRSLineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	grfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The increase (decrease) in borrowings resulting from foreign currency exchange rate changes measured in a currency different from the entity's presentation currency.

No definition available.

Name:	grfs_IncreaseDecreaseThroughNetExchangeDifferencesBorrowings
Namespace Prefix:	grfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the increase in borrowings through drawdowns in the credit facility.

No definition available.

Name:	grfs_IncreaseInBorrowingsThroughDrawdowns
Namespace Prefix:	grfs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Percentage of consolidated EBITDA derived from group entities leaving guarantees under Credit Agreement.

No definition available.

Name:	grfs_PercentageOfConsolidatedEbitdaDerivedFromGroupEntitiesLeavingGuaranteesUnderCreditAgreement
Namespace Prefix:	grfs_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Percentage of credit facility drawn to trigger mandatory compliance with leverage ratio covenant.

No definition available.

Name:	grfs_PercentageOfCreditFacilityDrawnToTriggerMandatoryComplianceWithLeverageRatioCovenant
Namespace Prefix:	grfs_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

The extension period of revolving credit facility.

No definition available.

Name:	grfs_RevolvingCreditFacilityExtensionPeriod
Namespace Prefix:	grfs_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The amount of outstanding funds that the entity is obligated to repay.

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

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

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

No definition available.

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

Name:	ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_BorrowingsByNameAxis=grfs_IfrsRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_BorrowingsByNameAxis=grfs_RevolvingCreditFacilityDueNovember2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: