Retirement Benefit Plans , Net Periodic Cost and AOCI (Details) - Pension benefits - USD ($) $ in Millions	12 Months Ended
	Apr. 27, 2018	Apr. 28, 2017	Apr. 29, 2016
U.S. Pension Benefits
Net Periodic Benefit Cost
Service cost	$ 116	$ 117	$ 120
Interest cost	117	109	122
Expected return on plan assets	(205)	(195)	(180)
Amortization of prior service cost	1	1	0
Amortization of net actuarial loss	82	88	98
Settlement loss (gain)	16	0	(1)
Special termination benefits	0	60	0
Net periodic benefit cost	127	180	159
Amounts Recognized in AOCI
Net actuarial gain	(27)
Amortization of prior service cost	(1)
Amortization of net actuarial loss	(82)
Prior service cost	0
Effect of exchange rates	0
Settlement loss	(17)
Total recognized in accumulated other comprehensive loss	(127)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	0
Non-U.S. Pension Benefits
Net Periodic Benefit Cost
Service cost	67	70	81
Interest cost	28	26	31
Expected return on plan assets	(53)	(48)	(48)
Amortization of prior service cost	0	(1)	0
Amortization of net actuarial loss	18	17	20
Settlement loss (gain)	0	0	(10)
Special termination benefits	0	0	0
Net periodic benefit cost	60	$ 64	$ 74
Amounts Recognized in AOCI
Net actuarial gain	(88)
Amortization of prior service cost	0
Amortization of net actuarial loss	(18)
Prior service cost	(4)
Effect of exchange rates	37
Settlement loss	0
Total recognized in accumulated other comprehensive loss	(73)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	$ (13)