Retirement Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 27, 2012	Jan. 28, 2011	Jan. 27, 2012	Jan. 28, 2011
U.S. Pension Benefits
Net Periodic Benefit Cost
Service cost	$ 23	$ 22	$ 69	$ 66
Interest cost	22	19	66	57
Expected return on plan assets	(30)	(26)	(90)	(78)
Amortization of net actuarial loss	11	8	33	24
Net periodic benefit cost	26	23	78	69
Non-U.S. Pension Benefits
Net Periodic Benefit Cost
Service cost	11	9	33	27
Interest cost	7	6	21	18
Expected return on plan assets	(9)	(6)	(27)	(18)
Amortization of net actuarial loss	1	1	3	3
Net periodic benefit cost	10	10	30	30
Post-Retirement Benefits
Net Periodic Benefit Cost
Service cost	5	5	15	15
Interest cost	4	4	12	12
Expected return on plan assets	(4)	(3)	(12)	(9)
Amortization of net actuarial loss	1	1	3	3
Net periodic benefit cost	$ 6	$ 7	$ 18	$ 21