Note 8 - Employee Post-employment Benefits - Changes in the Amounts Recognized in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2016	May 31, 2016	Jun. 02, 2015
Pension Plan [Member]
Beginning of year	$ (17,149)		$ (17,086)
Net actuarial (loss)/gain	(1,891)		(1,782)
Amortization of prior service credit	1		1
Amortization of actuarial loss	2,218		1,718
End of year	(16,821)	$ (16,821)	(17,149)
Postretirement Medical and Life Benefits [Member]
Beginning of year	(994)	(994)	(1,017)
Net actuarial (loss)/gain		373	(111)
Amortization of prior service credit
Amortization of actuarial loss		130	134
End of year	$ (491)	$ (491)	$ (994)