Note 1 - Organization, Basis of Presentation, and Summary of Significant Accounting Policies - Fair Value of Assets and Liabilities (Details) - USD ($) $ in Thousands		Feb. 25, 2018	May 28, 2017
Investment in non-public company		$ 65,800	$ 63,600
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Investment in non-public company
Contingent consideration liability (2)	[1]
Total
Fair Value, Inputs, Level 1 [Member] | Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Interest rate swap (1)	[2]
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Investment in non-public company
Contingent consideration liability (2)	[1]
Total		1,467	688
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Interest rate swap (1)	[2]	1,467	688
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Investment in non-public company		65,800	63,600
Contingent consideration liability (2)	[1]	(5,400)	(5,900)
Total		60,400	57,700
Fair Value, Inputs, Level 3 [Member] | Interest Rate Swap [Member] | Fair Value, Measurements, Recurring [Member]
Interest rate swap (1)	[2]

[1] Included in Other non-current liabilities in the accompanying consolidated balance sheets.

[2] Included in Other assets in the accompanying consolidated balance sheets.