Loans, allowance for loan losses and credit quality - Impaired loans details (Details 6) - CHF (SFr) SFr in Millions	Dec. 31, 2019	Dec. 31, 2018
Recorded investment
Recorded investment, with a specific allowance	SFr 1,702	SFr 1,458
Recorded investment, without specific allowance	412	722
Gross impaired loans	2,114	2,180
Unpaid principal balance
Unpaid principal balance, with a specific allowance	1,598	1,366
Unpaid principal balance, without specific allowance	412	722
Unpaid principal balance	2,010	2,088
Associated specific allowance	608	607
Corporate and institutional
Recorded investment
Recorded investment, with a specific allowance	1,095	929
Recorded investment, without specific allowance	336	574
Gross impaired loans	1,431	1,503
Unpaid principal balance
Unpaid principal balance, with a specific allowance	1,047	887
Unpaid principal balance, without specific allowance	336	574
Unpaid principal balance	1,383	1,461
Associated specific allowance	463	461
Corporate and institutional \| Real estate
Recorded investment
Recorded investment, with a specific allowance	120	82
Recorded investment, without specific allowance	37	40
Gross impaired loans	157	122
Unpaid principal balance
Unpaid principal balance, with a specific allowance	111	73
Unpaid principal balance, without specific allowance	37	40
Associated specific allowance	11	10
Corporate and institutional \| Commercial and industrial loans
Recorded investment
Recorded investment, with a specific allowance	927	761
Recorded investment, without specific allowance	299	534
Gross impaired loans	1,226	1,295
Unpaid principal balance
Unpaid principal balance, with a specific allowance	889	730
Unpaid principal balance, without specific allowance	299	534
Associated specific allowance	415	400
Corporate and institutional \| Financial institutions
Recorded investment
Recorded investment, with a specific allowance	48	86
Recorded investment, without specific allowance	0	0
Gross impaired loans	48	86
Unpaid principal balance
Unpaid principal balance, with a specific allowance	47	84
Unpaid principal balance, without specific allowance	0	0
Associated specific allowance	37	51
Consumer
Recorded investment
Recorded investment, with a specific allowance	607	529
Recorded investment, without specific allowance	76	148
Gross impaired loans	683	677
Unpaid principal balance
Unpaid principal balance, with a specific allowance	551	479
Unpaid principal balance, without specific allowance	76	148
Unpaid principal balance	627	627
Associated specific allowance	145	146
Consumer \| Mortgages
Recorded investment
Recorded investment, with a specific allowance	317	278
Recorded investment, without specific allowance	75	144
Gross impaired loans	392	422
Unpaid principal balance
Unpaid principal balance, with a specific allowance	299	262
Unpaid principal balance, without specific allowance	75	144
Associated specific allowance	30	21
Consumer \| Loans collateralized by securities
Recorded investment
Recorded investment, with a specific allowance	122	77
Recorded investment, without specific allowance	0	1
Gross impaired loans	122	78
Unpaid principal balance
Unpaid principal balance, with a specific allowance	108	63
Unpaid principal balance, without specific allowance	0	1
Associated specific allowance	22	35
Consumer \| Consumer finance
Recorded investment
Recorded investment, with a specific allowance	168	174
Recorded investment, without specific allowance	1	3
Gross impaired loans	169	177
Unpaid principal balance
Unpaid principal balance, with a specific allowance	144	154
Unpaid principal balance, without specific allowance	1	3
Associated specific allowance	SFr 93	SFr 90

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
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- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

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-Publisher FASB
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
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-Publisher FASB
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