Note 8 - Employee Post-employment Benefits - Weighted-average Assumptions Used to Determine the Benefit Obligation (Details)	Jun. 06, 2017	May 31, 2016
Pension Plan [Member]
Rate of compensation increase	2.00%	2.00%
Discount rate	3.90%	4.00%
Postretirement Medical and Life Benefits [Member]
Rate of compensation increase	2.00%	2.00%
Discount rate	3.50%	3.50%

Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

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