Note 2 - Revenue Recognition (Details Textual) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | |
|---|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2019 |
Jun. 30, 2018 |
|
| Contract with Customer, Liability, Total | $ 11.5 | $ 11.5 | $ 9.3 |
| Contract with Customer, Liability, Revenue Recognized | $ 0.9 | $ 6.5 |
| X | ||||||||||
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|