Debt (Schedule of credit facilities) (Details) (USD $) In Billions, unless otherwise specified	May 25, 2014
Line of Credit Facility [Line Items]
Facility Amount	$ 3.1
Borrowed Amount	0.1
Committed Credit Facilities [Member]
Line of Credit Facility [Line Items]
Facility Amount	2.7
Borrowed Amount	0
Minimum Fixed Charge Coverage Ratio	2.5
Committed Credit Facilities [Member] | April 2017 [Member]
Line of Credit Facility [Line Items]
Facility Amount	1.7
Borrowed Amount	0
Committed Credit Facilities [Member] | May 2019 [Member]
Line of Credit Facility [Line Items]
Facility Amount	1.0
Borrowed Amount	0
Committed Credit Facilities [Member] | April 2015 [Member]
Line of Credit Facility [Line Items]
Facility Amount	1.0
Uncommitted Credit Facility [Member]
Line of Credit Facility [Line Items]
Facility Amount	0.4
Borrowed Amount	$ 0.1