Note 2 - Revenue from Contracts with Customers - Changes in Contract Assets and Liabilities (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Contract assets, balance | ||
| Contract assets added | 210,688 | |
| Contract assets, balance | 210,688 | |
| Contract liabilities, balance | 464,223 | 318,552 |
| Contract liabilities added | 1,465,299 | 861,637 |
| Revenue recognized | (982,638) | (715,966) |
| Contract liabilities, balance | $ 946,884 | $ 464,223 |
| X | ||||||||||
- Definition Represents the amount of contract assets added during the period, resulting in an increase to the asset from contract with customer. No definition available.
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| X | ||||||||||
- Definition Additions in the period to the contract with customer, liability. No definition available.
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| 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. No definition available.
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| X | ||||||||||
- Definition Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| 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
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