Retirement Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 29, 2016	Jan. 23, 2015	Jan. 29, 2016	Jan. 23, 2015
U.S. Pension Benefits [Member]
Net Periodic Benefit Cost
Service cost	$ 30	$ 26	$ 90	$ 78
Interest cost	31	26	93	78
Expected return on plan assets	(45)	(39)	(135)	(117)
Amortization of net actuarial loss	24	16	72	48
Net periodic benefit cost	40	29	120	87
Non-U.S. Pension Benefits [Member]
Net Periodic Benefit Cost
Service cost	22	15	66	45
Interest cost	9	8	27	24
Expected return on plan assets	(13)	(10)	(39)	(30)
Amortization of net actuarial loss	6	3	18	9
Net periodic benefit cost	$ 24	$ 16	$ 72	$ 48