Equity (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended		3 Months Ended	6 Months Ended
	Mar. 31, 2016 SFr / shares $ / shares shares	Mar. 31, 2016 $ / shares shares	Mar. 25, 2016 USD ($) item	Mar. 25, 2016 USD ($) item shares	Mar. 27, 2015 USD ($) shares	Sep. 25, 2015 USD ($)
Equity
Maximum percentage of additional shares which the board is authorized to issue subject to certain conditions	50.00%	50.00%
Cancellation of treasury shares (in shares) | shares	31	31
Dividend or cash distribution approved (in currency per share) | (per share)	SFr 1.48	$ 1.48
Cash distribution quarterly installment payable (in dollars per share) | $ / shares	SFr 0.37	$ 0.37
Unpaid portion of the dividend payment recorded in accrued and other current liabilities			$ 529	$ 529		$ 260
Number of quarterly dividend installments | item			4	4
Share repurchase program, increase in authorized amount			$ 1,000
Number of common shares repurchased | shares				40	4
Amount repurchased				$ 2,415	$ 284
Amount available for repurchase, at end of period			$ 1,300	$ 1,300