Accumulated other comprehensive income (Details) (CHF) In Millions, unless otherwise specified					12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2011 Gains/(losses) on cash flow hedges	Dec. 31, 2010 Gains/(losses) on cash flow hedges	Dec. 31, 2009 Gains/(losses) on cash flow hedges	Dec. 31, 2011 Cumulative translation adjustments	Dec. 31, 2010 Cumulative translation adjustments	Dec. 31, 2009 Cumulative translation adjustments	Dec. 31, 2011 Unrealized gains/(losses) on securities	Dec. 31, 2010 Unrealized gains/(losses) on securities	Dec. 31, 2009 Unrealized gains/(losses) on securities	Dec. 31, 2011 Actuarial gains/(losses)	Dec. 31, 2010 Actuarial gains/(losses)	Dec. 31, 2009 Actuarial gains/(losses)	Dec. 31, 2011 Net prior service credit/ (cost)	Dec. 31, 2010 Net prior service credit/ (cost)	Dec. 31, 2009 Net prior service credit/ (cost)	Dec. 31, 2011 Accumulated other comprehensive income	Dec. 31, 2010 Accumulated other comprehensive income	Dec. 31, 2009 Accumulated other comprehensive income
Increase (Decrease) in Accumulated other Comprehensive Income (CHF million)
Balance	(15,134)	(14,555)	(11,638)	(10,939)	(33)	(41)	(145)	(11,470)	(8,770)	(8,211)	117	110	63	(3,136)	(2,891)	(2,543)	(33)	(46)	(103)	(14,555)	(11,638)	(10,939)
Increase/(decrease)					(5)	46	30	(324)	(2,822)	(609)	6	0	62	(720)	(338)	(368)	383	0	30	(660)	(3,114)	(855)
Increase/(decrease) due to equity method investments					1	(15)	87	0	0	0	0	1	0	0	0	0	0	0	0	(1)	(14)	87
Reclassification adjustments, included in net income					27	(23)	(13)	16	(13)	50	(24)	6	(15)	105	93	20	12	13	27	82	76	69
Cumulative effect of accounting changes, net of tax						0			135			0			0			0			135
Balance	(15,134)	(14,555)	(11,638)	(10,939)	(66)	(33)	(41)	(11,778)	(11,470)	(8,770)	99	117	110	(3,751)	(3,136)	(2,891)	362	(33)	(46)	(15,134)	(14,555)	(11,638)

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e653-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 14, 17, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e637-108580

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e681-108580

+ Details

- Definition

The after tax effect on other comprehensive income of a change in accounting principle recognized in the period, which occurred before retrospective adjustments were required, or is in lieu of retrospective adjustments.

+ References+ Details