Recently issued accounting standards (Details) (Accounting Standards Update 2009-17 Consolidations (Topic 810), CHF) In Billions, unless otherwise specified	Jan. 02, 2010
Accounting Standards Update 2009-17 Consolidations (Topic 810)
Accounting change
Cumulative effect of accounting changes, increase (decrease) in net assets	15.0
Cumulative effect of accounting changes, increase / decrease in shareholders' equity, net of tax	2.2

Amount of the cumulative effect of the change in accounting principle or new accounting pronouncement on equity in the statement of financial position as of the beginning of the earliest period presented.

No definition available.

Name:	cs_NewAccountingPronouncementOrChangeInAccountingPrincipleCumulativeEffectOfChangeOnEquity
Namespace Prefix:	cs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant