Note 1 - Organization, Basis of Presentation, and Summary of Significant Accounting Policies - Fair Value of Assets and Liabilities (Details) - USD ($) $ in Thousands	Aug. 26, 2018	May 27, 2018
Investment in non-public company	$ 67,500	$ 66,500
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Investment in non-public company
Total assets
Contingent consideration liability
Total liabilities
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Interest Rate Swap [Member]
Interest rate swap contract
Interest rate swap contract
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Investment in non-public company
Total assets	1,466	1,529
Contingent consideration liability
Total liabilities	54
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Interest Rate Swap [Member]
Interest rate swap contract	1,466	1,529
Interest rate swap contract	54
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Investment in non-public company	67,500	66,500
Total assets	67,500	66,500
Contingent consideration liability	4,000	4,000
Total liabilities	4,000	4,000
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member] \| Interest Rate Swap [Member]
Interest rate swap contract
Interest rate swap contract

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Fair value of financial and nonfinancial obligations.

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