Retirement Benefit Plans (Details) - Pension plans - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 25, 2019	Jan. 26, 2018	Jan. 25, 2019	Jan. 26, 2018
U.S.
Net Periodic Benefit Cost
Service cost	$ 27	$ 29	$ 81	$ 87
Interest cost	33	29	99	89
Expected return on plan assets	(54)	(51)	(162)	(155)
Amortization of net actuarial loss	19	20	57	60
Plan settlement	0	15	0	15
Net periodic benefit cost	25	42	75	96
Non-U.S.
Net Periodic Benefit Cost
Service cost	15	17	45	51
Interest cost	7	7	21	21
Expected return on plan assets	(14)	(13)	(42)	(39)
Amortization of net actuarial loss	3	4	9	12
Plan settlement	0	0	0	0
Net periodic benefit cost	$ 11	$ 15	$ 33	$ 45