Consolidated Statements of Changes in Stockholders' Equity (Parentheticals) - $ / shares	May 28, 2017	May 29, 2016	May 31, 2015
Common Stock [Member] | Minimum [Member]
Issuance of common stock, per share (in dollars per share)	$ 5.63	$ 5.63	$ 5.63
Common Stock [Member] | Maximum [Member]
Issuance of common stock, per share (in dollars per share)	11.63	$ 9.01	$ 8.19
Issuance of common stock, per share (in dollars per share)	$ 13.65