Transfers of financial assets (TFA) - Securitizations (Details) - CHF (SFr) SFr in Millions	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021
CMBS
Transfers of financial assets disclosures
Net gain/(loss)	SFr 5	SFr 0
Proceeds from transfer of assets	2,819	999
Cash received on interests that continue to be held	22	26
RMBS
Transfers of financial assets disclosures
Net gain/(loss)	(1)	62
Proceeds from transfer of assets	6,799	20,876
Purchases of previously transferred financial assets or their underlying collateral	0	(1,072)
Servicing fees	0	1
Cash received on interests that continue to be held	531	430
Other asset-backed financings
Transfers of financial assets disclosures
Net gain/(loss)	23	47
Proceeds from transfer of assets	3,808	6,802
Purchases of previously transferred financial assets or their underlying collateral	(997)	(699)
Servicing fees	97	81
Cash received on interests that continue to be held	36	7
Bank \| CMBS
Transfers of financial assets disclosures
Net gain/(loss)	5	0
Proceeds from transfer of assets	2,819	999
Cash received on interests that continue to be held	22	26
Bank \| RMBS
Transfers of financial assets disclosures
Net gain/(loss)	(1)	62
Proceeds from transfer of assets	6,799	20,876
Purchases of previously transferred financial assets or their underlying collateral	0	(1,072)
Servicing fees	0	1
Cash received on interests that continue to be held	531	430
Bank \| Other asset-backed financings
Transfers of financial assets disclosures
Net gain/(loss)	23	47
Proceeds from transfer of assets	3,808	6,802
Purchases of previously transferred financial assets or their underlying collateral	(997)	(699)
Servicing fees	97	81
Cash received on interests that continue to be held	SFr 36	SFr 7

Cash Flows between a transferor and a transferee attributable to newly transferred assets related to either a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Cash Flows between a transferor and a transferee attributable to purchases of previously transferred financial assets (or its underlying collateral) related to a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (d)(3)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cash flows between transferor and transferee in payment of service fees in advance, prior to or in contemplation of a securitization, asset-backed financing arrangement, or similar transfer in which the transferor will have continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (d)(4)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cash Flows between a transferee and a transferor attributable to servicing fees related to a securitization, asset-backed financing arrangement, or similar transfer in which the transferor has continuing involvement with the transferred financial assets underlying the transaction (including, but not limited to, servicing, recourse, and restrictions on transferor's interests in the transferred financial assets).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (d)(4)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

+ Details

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

- Definition

Reflects, by transferred financial asset type, the amount of sales proceeds in excess of or deficient from the sum of the carrying amounts of transferred financial assets plus transaction costs, including those transactions in which the seller/transferor has continuing involvement with the financial assets that have been transferred.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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