Provision for credit losses (Details) - CHF (SFr) SFr in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Provision for credit losses
Loans held at amortized cost	SFr 188	SFr (23)	SFr 863
Other financial assets held at amortized cost	(132)	4,291	24
Off-balance sheet credit exposures	(40)	(63)	209
Provision for credit losses	16	4,205	1,096
Archegos Capital Management [Member]
Provision for credit losses
Other financial assets held at amortized cost	(155)	4,307
Bank
Provision for credit losses
Loans held at amortized cost	190	(23)	863
Other financial assets held at amortized cost	(135)	4,295	19
Off-balance sheet credit exposures	(40)	(63)	210
Provision for credit losses	15	4,209	SFr 1,092
Bank \| Archegos Capital Management [Member]
Provision for credit losses
Other financial assets held at amortized cost	SFr (155)	SFr 4,307

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Name:	us-gaap_ProvisionForLoanLeaseAndOtherLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration