Retirement Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 24, 2014	Jan. 25, 2013	Jan. 24, 2014	Jan. 25, 2013
U.S. Pension Benefits
Net Periodic Benefit Cost
Service cost	$ 27	$ 26	$ 81	$ 78
Interest cost	24	23	72	69
Expected return on plan assets	(35)	(32)	(105)	(96)
Amortization of net actuarial loss	21	18	63	54
Net periodic benefit cost	37	35	111	105
Non-U.S. Pension Benefits
Net Periodic Benefit Cost
Service cost	13	11	41	33
Interest cost	7	7	21	21
Expected return on plan assets	(8)	(8)	(26)	(24)
Amortization of net actuarial loss	3	2	7	6
Net periodic benefit cost	15	12	43	36
Post-Retirement Benefits
Net Periodic Benefit Cost
Service cost	5	5	15	15
Interest cost	4	4	10	12
Expected return on plan assets	(5)	(4)	(15)	(12)
Amortization of net actuarial loss	0	1	0	3
Net periodic benefit cost	$ 4	$ 6	$ 10	$ 18