Equity and Comprehensive Income (Details) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended				1 Months Ended	6 Months Ended
	Mar. 06, 2013 USD ($) item	Feb. 20, 2013 USD ($)	Jan. 29, 2013 USD ($)	Nov. 15, 2012 USD ($)	Apr. 30, 2011 USD ($)	Mar. 29, 2013 USD ($)	Mar. 06, 2013 CHF	Sep. 17, 2012 USD ($) item
Equity and Comprehensive Income
Cash dividend payable (in dollars per share)	$ 0.64							$ 0.30
Number of quarterly installments of dividend payable	4							2
Accrued dividend						$ 296,000,000		$ 139,000,000
Installment of dividend paid (in dollars per share)		$ 0.15		$ 0.15
Installment of dividend payable (in dollars per share)	$ 0.16
Share Repurchase Program
Amount approved under the share repurchase program			600,000,000		1,000,000,000
Number of shares repurchased						7
Value of shares repurchased						200,000,000
Amount outstanding under the 2013 share repurchase program						600,000,000
Share capital after reduction, in CHF							243,181,525
Share capital prior to reduction, in CHF							3,258,632,435
Common shares, par value after reduction (in CHF per share)							0.50
Common shares, par value prior to reduction (in CHF per share)							6.70
Share capital, increase enity contribution value, in CHF							3,015,450,910