| Note 6 - Leases (Details Textual) $ in Millions | 3 Months Ended | 
|---|---|
| Sep. 30, 2020  USD ($) | |
| Variable Lease, Cost | $ 0.7 | 
| Fixed Lease, Cost | $ 3.5 | 
| Maximum [Member] | |
| Lessee, Operating Lease, Renewal Term (Year) | 5 years | 
| X | ||||||||||
| 
- Definition Represents the amount of fixed lease cost. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
 | 
| X | ||||||||||
| 
- Definition Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
 | 
| X | ||||||||||
| 
- Details 
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