v3.2.0.727

Shareholders' equity Shareholders' equity (Details) $ / shares in Units, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) SFr / shares shares	Jun. 30, 2014 USD ($) $ / shares shares	Jun. 30, 2014 USD ($) SFr / shares	Jun. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) SFr / shares shares	Jun. 30, 2014 USD ($) $ / shares shares	Jun. 30, 2014 USD ($) SFr / shares	Jun. 30, 2013 $ / shares	Jun. 30, 2015 SFr / shares	May. 31, 2015 $ / shares	Jan. 01, 2015 USD ($)	Dec. 31, 2014 SFr / shares shares	May. 31, 2014 $ / shares	Nov. 30, 2013 USD ($)	May. 31, 2013 $ / shares
Equity, Class of Treasury Stock [Line Items]
Common Shares in treasury, shares | shares	19,018,131	19,018,131			19,018,131	19,018,131							14,172,726
Par Value Reduction | (per share)	$ 0	SFr 0	$ 0.65	SFr 0.58	$ 0.65	SFr 0.62	$ 1.16	SFr 1.03
Dividends Declared From Additional Paid In Capital | (per share)	0.67	0.62	0.00	0	0.67	0.62	0.24	0.20
Annual dividend per share approved by shareholders | $ / shares											$ 2.68			$ 2.60		$ 2.04
Increase to dividend approved by shareholders in January | $ / shares							0.12
Dividends declared per common share | (per share)	0.67	SFr 0.62	$ 0.65	SFr 0.58	1.32	SFr 1.24	1.40	SFr 1.23
Common Stock, Dividend Rate, Per-Dollar-Amount | $ / shares	$ 0.65				$ 0.67				$ 0.51
Common Stock, Dividend Rate, Per-Dollar-Amount After Increase | $ / shares							$ 0.63
Common Shares, par value | SFr / shares										SFr 24.15			SFr 24.77
2015 Stock Repurchase Plan [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares repurchased	$ 394				$ 734
Repurchase of outstanding common shares, shares | shares	3,650,200				6,677,663
Share repurchase authorization remains	$ 766	SFr 766			$ 766	SFr 766
Stock repurchase program, authorized amount												$ 1,500
November 2013 Stock Repurchase Plan [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares repurchased			$ 237				$ 569
Repurchase of outstanding common shares, shares | shares			2,306,000				5,793,882
Share repurchase authorization remains			$ 1,374	SFr 1,374			$ 1,374	SFr 1,374
Stock repurchase program, authorized amount															$ 2,000

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