Retirement Benefit Plans , Actuarial Assumptions and Plan Assets Target Allocations (Details) - Pension benefits	12 Months Ended
	Apr. 26, 2019	Apr. 27, 2018	Apr. 28, 2017
U.S. Pension Benefits
Critical assumptions – projected benefit obligation:
Rate of compensation increase	3.90%	3.90%	3.90%
Critical assumptions – net periodic benefit cost:
Expected return on plan assets	7.90%	7.90%	8.20%
Rate of compensation increase	3.90%	3.90%	3.90%
Plan Assets Target Allocations
Target Allocation	100.00%
Actual Allocation	100.00%	100.00%
U.S. Pension Benefits | Equity securities
Plan Assets Target Allocations
Target Allocation	49.00%
Actual Allocation	50.00%	49.00%
U.S. Pension Benefits | Debt securities
Plan Assets Target Allocations
Target Allocation	32.00%
Actual Allocation	34.00%	32.00%
U.S. Pension Benefits | Other
Plan Assets Target Allocations
Target Allocation	19.00%
Actual Allocation	16.00%	19.00%
U.S. Pension Benefits | Minimum
Critical assumptions – projected benefit obligation:
Discount rate	3.90%	4.20%	3.70%
Critical assumptions – net periodic benefit cost:
Discount rate – benefit obligation	4.20%	4.00%	3.55%
Discount rate – service cost	4.10%	3.70%	3.60%
Discount rate – interest cost	4.00%	3.45%	2.90%
U.S. Pension Benefits | Maximum
Critical assumptions – projected benefit obligation:
Discount rate	4.20%	4.35%	4.30%
Critical assumptions – net periodic benefit cost:
Discount rate – benefit obligation	4.30%	4.30%	4.30%
Discount rate – service cost	4.40%	4.45%	4.45%
Discount rate – interest cost	4.10%	3.80%	3.80%
Non-U.S. Pension Benefits
Critical assumptions – projected benefit obligation:
Rate of compensation increase	2.87%	2.88%	2.89%
Critical assumptions – net periodic benefit cost:
Expected return on plan assets	4.23%	4.20%	4.45%
Rate of compensation increase	2.88%	2.89%	2.83%
Non-U.S. Pension Benefits | Equity securities
Plan Assets Target Allocations
Target Allocation	38.00%
Non-U.S. Pension Benefits | Debt securities
Plan Assets Target Allocations
Target Allocation	30.00%
Non-U.S. Pension Benefits | Other
Plan Assets Target Allocations
Target Allocation	32.00%
Non-U.S. Pension Benefits | Minimum
Critical assumptions – projected benefit obligation:
Discount rate	0.40%	0.70%	0.45%
Critical assumptions – net periodic benefit cost:
Discount rate – benefit obligation	0.50%	0.45%	0.25%
Discount rate – service cost	0.50%	0.20%	0.05%
Discount rate – interest cost	0.50%	0.45%	0.30%
Non-U.S. Pension Benefits | Maximum
Critical assumptions – projected benefit obligation:
Discount rate	13.90%	11.00%	11.40%
Critical assumptions – net periodic benefit cost:
Discount rate – benefit obligation	11.00%	11.40%	10.20%
Discount rate – service cost	11.00%	11.40%	10.20%
Discount rate – interest cost	11.00%	11.40%	10.20%