Retirement Benefit Plans (Details) - Pension plans - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 26, 2018	Oct. 27, 2017	Oct. 26, 2018	Oct. 27, 2017
U.S.
Net Periodic Benefit Cost
Service cost	$ 27	$ 29	$ 54	$ 58
Interest cost	33	30	66	60
Expected return on plan assets	(54)	(52)	(108)	(104)
Amortization of net actuarial loss	19	20	38	40
Net periodic benefit cost	25	27	50	54
Non-U.S.
Net Periodic Benefit Cost
Service cost	15	17	30	34
Interest cost	7	7	14	14
Expected return on plan assets	(14)	(13)	(28)	(26)
Amortization of net actuarial loss	3	4	6	8
Net periodic benefit cost	$ 11	$ 15	$ 22	$ 30