Pension and Postretirement Benefits (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	May 01, 2011	May 02, 2010	May 01, 2011	May 02, 2010
Pension [Member]
Service cost	$ 15	$ 14	$ 44	$ 41
Interest cost	30	30	91	91
Expected return on plan assets	(45)	(43)	(134)	(128)
Settlement costs		12		12
Amortization of prior service cost/(credit)		1		2
Recognized net actuarial loss	17	12	52	36
Net periodic benefit expense	17	26	53	54
Postretirement [Member]
Service cost		1	2	3
Interest cost	5	4	14	14
Expected return on plan assets
Settlement costs
Amortization of prior service cost/(credit)			(1)
Recognized net actuarial loss	2	1	6	1
Net periodic benefit expense	7	6	21	18
U.S. Pension Plans [Member]
Contribution to pension plans			100
Expected contribution to pension plan remainder of year	0		0
Non U.S. Pension Plans [Member]
Contribution to pension plans			40
Expected contribution to pension plan remainder of year	$ 4		$ 4