Interest Expense, Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Jan. 23, 2015	Jan. 24, 2014	Jan. 23, 2015	Jan. 24, 2014
Interest Income and Interest Expense
Interest Income	$ (95)mdt_InterestIncome	$ (67)mdt_InterestIncome	$ (273)mdt_InterestIncome	$ (178)mdt_InterestIncome
Interest Expense	176us-gaap_InterestCostsIncurred	92us-gaap_InterestCostsIncurred	367us-gaap_InterestCostsIncurred	276us-gaap_InterestCostsIncurred
Interest expense, net	$ 81mdt_InterestExpenseIncomeNet	$ 25mdt_InterestExpenseIncomeNet	$ 94mdt_InterestExpenseIncomeNet	$ 98mdt_InterestExpenseIncomeNet

Net amount of interest expense or income. Interest expense includes the expense associated with the interest paid on outstanding borrowings, including short- and long-term instruments, and the amortization of debt issuance costs and debt discounts. Interest income includes interest earned on cash and cash equivalents, short- and long-term investments, the net realized gains or losses on the sale of available-for-sale securities, and the net realized and unrealized gains or losses on trading securities.

No definition available.

Name:	mdt_InterestExpenseIncomeNet
Namespace Prefix:	mdt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration