Investment securities - Maturities of amortized costs/FV/Avg yield (Details 5) - CHF (SFr) SFr in Millions	Dec. 31, 2022	Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Due within 1 year, amortized cost	SFr 0
Due from 1 to 5 years, amortized cost	921
Due from 5 to 10 years, amortized cost	0
Debt securities held-to-maturity, amortized cost	921
Accrued interest excluded from amortized cost base of total Debt securities held-to-maturity	10
Due within 1 year, fair value	0
Due from 1 to 5 years, fair value	881
Due from 5 to 10 years, fair value	0
Debt securities held-to-maturity, fair value	SFr 881
Due within 1 year, average yield (as a percent)	0.00%
Due from 1 to 5 years, average yield (as a percent)	3.94%
Due from 5 to 10 years, average yield (as a percent)	0.00%
Total, average yield (as a percent)	3.94%
Bank
Schedule of Held-to-maturity Securities [Line Items]
Due within 1 year, amortized cost	SFr 0
Due from 1 to 5 years, amortized cost	921
Due from 5 to 10 years, amortized cost	0
Debt securities held-to-maturity, amortized cost	921
Accrued interest excluded from amortized cost base of total Debt securities held-to-maturity	10	SFr 0
Due within 1 year, fair value	0
Due from 1 to 5 years, fair value	881
Due from 5 to 10 years, fair value	0
Debt securities held-to-maturity, fair value	SFr 881
Due within 1 year, average yield (as a percent)	0.00%
Due from 1 to 5 years, average yield (as a percent)	3.94%
Due from 5 to 10 years, average yield (as a percent)	0.00%
Total, average yield (as a percent)	3.94%

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- Definition

Amount, before allowance for credit loss, of accrued interest on investment in debt security measured at amortized cost (held-to-maturity).

+ References

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-Publisher FASB
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Weighted average yield of investment in debt security measured at amortized cost (held-to-maturity) maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Weighted average yield of investment in debt security measured at amortized cost (held-to-maturity) maturing in second through fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Weighted average yield of investment in debt security measured at amortized cost (held-to-maturity) maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity) with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year following current statement of financial position date. For interim and annual periods when interim period is reported on rolling approach.

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