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

The increase (decrease) in equity, as a result of an increase in a designated risk component that was reasonably possible at the end of the reporting period.

No definition available.

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

The increase (decrease) in profit due to foreign exchange gain (loss) due to reasonably possible decrease in designated risk component.

No definition available.

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

The increase (decrease) in profit due to foreign exchange gain (loss) due to reasonably possible increase in designated risk component.

No definition available.

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

The reasonably possible percentage of the decrease in the designated risk component used to determine the value of the financial instrument. Excludes defined benefit plan obligations.

No definition available.

Name:	grfs_PercentageOfReasonablyPossibleDecreaseInRiskAssumption
Namespace Prefix:	grfs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The reasonably possible percentage of the increase in the designated risk component used to determine the value of the financial instrument. Excludes defined benefit plan obligations.

No definition available.

Name:	grfs_PercentageOfReasonablyPossibleIncreaseInRiskAssumption
Namespace Prefix:	grfs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The spot exchange rate at the end of the reporting period. Exchange rate is the ratio of exchange for two currencies. Spot exchange rate is the exchange rate for immediate delivery.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_ClosingForeignExchangeRate
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

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

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

No definition available.

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

The amount of risk exposure associated with financial instruments with a shared characteristic that identifies a concentration of risks. [Refer: Financial instruments, class [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph B8
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_B8_c&doctype=Appendix&subtype=B
-URIDate 2019-03-27

Name:	ifrs-full_RiskExposureAssociatedWithInstrumentsSharingCharacteristic
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

Name:	srt_CurrencyAxis=currency_USD
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_CurrencyAxis=currency_EUR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=ifrs-full_TradeReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=grfs_ReceivablesDueFromGroupCompaniesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=grfs_LoansReceivableFromGroupCompaniesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=grfs_CashCashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=grfs_TradeAndOtherPayablesToSuppliersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=grfs_PayablesToGroupCompaniesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_ClassesOfFinancialInstrumentsAxis=grfs_LoansPayableToGroupCompaniesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: