Contract revenues, A-syn and TDP-43 PET tracers - 2016 agreement with Biogen (Details) SFr in Thousands	12 Months Ended
Dec. 31, 2021 CHF (SFr) Obligation	Dec. 31, 2020 CHF (SFr)	Dec. 31, 2019 CHF (SFr)
Contract revenues [Abstract]
Recognized revenues	SFr 0	SFr 15,431	SFr 110,456
2016 Agreement with Biogen [Member]
Contract revenues [Abstract]
Recognized revenues	SFr 0	0	1,063
A-syn and TDP-43 PET Tracers [Member] \| 2016 Agreement with Biogen [Member]
Contract revenues [Abstract]
Number of performance obligations identified \| Obligation	2
Recognized revenues	SFr 0	SFr 0	SFr 1,100

The amount of revenue from contracts with customers. A customer is a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ordinary activities in exchange for consideration.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2021-01-01
-Paragraph 113
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2021-en-r&anchor=para_113_a&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2021-01-01
-Paragraph 114
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2021-en-r&anchor=para_114&doctype=Standard
-URIDate 2021-03-24

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration