Summary of Significant Accounting Policies - Financial Assets (Details)	12 Months Ended
Dec. 31, 2017
Summary of Significant Accounting Policies
Equity impairment indicator, decline in fair value (as percent)	20.00%
Impairment indicator, period of decline in fair value	9 months

The period of decline in fair value of equity investment considered as impairment indicator for which financial income effect is recognized, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	sap_EquityInvestmentImpairmentIndicatorPeriodOfDeclineInFairValue
Namespace Prefix:	sap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration