Note 17 - Contracts With Customers - Concentration of Customers (Details)	12 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Revenue Benchmark [Member] \| Customer Concentration Risk [Member] \| El Camino, Los Gatos, & Other Facilities [Member]
Concentration Risk, Percentage	26.80%	22.10%	24.20%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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