Retirement Plans (Details 7) - USD ($) $ in Millions	Sep. 25, 2015	Sep. 26, 2014	Sep. 27, 2013
U.S. Plans
Summary of asset fair value
Fair value of plan assets	$ 879	$ 978	$ 931
U.S. Plans | Fair Value
Summary of asset fair value
Fair value of plan assets	879	978
U.S. Plans | U.S. equity securities | Level 1
Summary of asset fair value
Fair value of plan assets	245	210
U.S. Plans | U.S. equity securities | Fair Value
Summary of asset fair value
Fair value of plan assets	245	210
U.S. Plans | Non-U.S. equity securities | Level 1
Summary of asset fair value
Fair value of plan assets	149	209
U.S. Plans | Non-U.S. equity securities | Fair Value
Summary of asset fair value
Fair value of plan assets	149	209
U.S. Plans | Government bonds | Level 2
Summary of asset fair value
Fair value of plan assets	64	87
U.S. Plans | Government bonds | Fair Value
Summary of asset fair value
Fair value of plan assets	64	87
U.S. Plans | Corporate bonds | Level 2
Summary of asset fair value
Fair value of plan assets	404	445
U.S. Plans | Corporate bonds | Fair Value
Summary of asset fair value
Fair value of plan assets	404	445
U.S. Plans | Other | Level 2
Summary of asset fair value
Fair value of plan assets	3	13
U.S. Plans | Other | Fair Value
Summary of asset fair value
Fair value of plan assets	3	13
U.S. Plans | Subtotal | Level 1
Summary of asset fair value
Fair value of plan assets	394	419
U.S. Plans | Subtotal | Level 2
Summary of asset fair value
Fair value of plan assets	471	545
U.S. Plans | Subtotal | Fair Value
Summary of asset fair value
Fair value of plan assets	865	964
U.S. Plans | Items to reconcile to fair value of plan assets | Fair Value
Summary of asset fair value
Fair value of plan assets	14	14
Non-U.S. Plans
Summary of asset fair value
Fair value of plan assets	1,167	1,177	$ 1,113
Non-U.S. Plans | Fair Value
Summary of asset fair value
Fair value of plan assets	1,167	1,177
Non-U.S. Plans | U.S. equity securities | Level 1
Summary of asset fair value
Fair value of plan assets	60	54
Non-U.S. Plans | U.S. equity securities | Fair Value
Summary of asset fair value
Fair value of plan assets	60	54
Non-U.S. Plans | Non-U.S. equity securities | Level 1
Summary of asset fair value
Fair value of plan assets	54	65
Non-U.S. Plans | Non-U.S. equity securities | Fair Value
Summary of asset fair value
Fair value of plan assets	54	65
Non-U.S. Plans | Commingled equity funds | Level 2
Summary of asset fair value
Fair value of plan assets	421	434
Non-U.S. Plans | Commingled equity funds | Fair Value
Summary of asset fair value
Fair value of plan assets	421	434
Non-U.S. Plans | Government bonds | Level 2
Summary of asset fair value
Fair value of plan assets	202	211
Non-U.S. Plans | Government bonds | Fair Value
Summary of asset fair value
Fair value of plan assets	202	211
Non-U.S. Plans | Corporate bonds | Level 2
Summary of asset fair value
Fair value of plan assets	13	19
Non-U.S. Plans | Corporate bonds | Fair Value
Summary of asset fair value
Fair value of plan assets	13	19
Non-U.S. Plans | Commingled bond funds | Level 2
Summary of asset fair value
Fair value of plan assets	171	203
Non-U.S. Plans | Commingled bond funds | Fair Value
Summary of asset fair value
Fair value of plan assets	171	203
Non-U.S. Plans | Other | Level 2
Summary of asset fair value
Fair value of plan assets	142	85
Non-U.S. Plans | Other | Level 3
Summary of asset fair value
Fair value of plan assets	84	78
Non-U.S. Plans | Other | Fair Value
Summary of asset fair value
Fair value of plan assets	226	163
Non-U.S. Plans | Subtotal | Level 1
Summary of asset fair value
Fair value of plan assets	114	119
Non-U.S. Plans | Subtotal | Level 2
Summary of asset fair value
Fair value of plan assets	949	952
Non-U.S. Plans | Subtotal | Level 3
Summary of asset fair value
Fair value of plan assets	84	78
Non-U.S. Plans | Subtotal | Fair Value
Summary of asset fair value
Fair value of plan assets	1,147	1,149
Non-U.S. Plans | Items to reconcile to fair value of plan assets | Fair Value
Summary of asset fair value
Fair value of plan assets	$ 20	$ 28