Guarantees, commitments and risks - Sensitivity EUR (Details) - Strategic liquidity risk - Euro - EUR (€) € in Thousands	Dec. 31, 2019	Dec. 31, 2018
Guarantees, commitments and risks
Value at risk	€ 330	€ 250
Minimum
Guarantees, commitments and risks
Value at risk	310	250
Maximum
Guarantees, commitments and risks
Value at risk	370	350
Average
Guarantees, commitments and risks
Value at risk	€ 350	€ 290

The measure of a potential loss exposure as a result of future market movements, based on a specified confidence interval and measurement horizon.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2019-01-01
-Paragraph 41
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2019-en-r&anchor=para_41&doctype=Standard
-URIDate 2019-03-27

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