Note 3 - Investments (Details Textual) | Mar. 17, 2021USD ($)$ / sharesshares | Mar. 06, 2019$ / sharesshares | Oct. 02, 2015$ / sharesshares | Mar. 30, 2012USD ($)$ / sharesshares | Mar. 31, 2021USD ($)$ / shares | Dec. 31, 2020USD ($)$ / shares | Dec. 31, 2017$ / sharesshares | Dec. 31, 2015USD ($)shares | Dec. 31, 2014USD ($)shares | Mar. 05, 2019shares |
Salon Media Group, Inc [Member] | | | | | | | | | | |
Disposal Group, Including Discontinued Operation, Consideration, Per Share (in dollars per share) | $ / shares | | $ 0.01 | | | | | | | | |
Arcimoto, Inc. [Member] | | | | | | | | | | |
Share Price (in dollars per share) | $ / shares | | | | | $ 13.23 | $ 13.23 | | | | |
Arcimoto, Inc. [Member] | Reverse Stock Split [Member] | | | | | | | | | | |
Stockholders' Equity Note, Stock Split, Conversion Ratio | | | | | | | 2 | | | |
TangoMe, Inc, Series A Preferred Stock [Member] | | | | | | | | | | |
Gain (Loss) on Investments, Total | $ | | | | | $ 0 | $ 0 | | | | |
Investment Owned, at Fair Value | $ | | | | | 2,574,666 | 2,574,666 | | | | |
TangoMe, Inc, Series A Preferred Stock [Member] | Chief Executive Officer [Member] | | | | | | | | | | |
Investment Purchased, Shares (in shares) | shares | | | | 468,121 | | | | | | |
Investment Purchased, Price Per Share (in dollars per share) | $ / shares | | | | $ 2.14 | | | | | | |
Investment Purchased, Value | $ | | | | $ 1,000,000 | | | | | | |
Salon Media Group, Inc, Common Stock [Member] | | | | | | | | | | |
Investment Owned, Balance, Shares (in shares) | shares | | | | | | | | | | 1,926,857 |
Investment Owned, Shares, Write-Off (in shares) | shares | | 1,926,857 | | | | | | | | |
Flexi International Software Stock [Member] | | | | | | | | | | |
Investment Owned, Balance, Shares (in shares) | shares | | | | | | | | | 78,000 | |
Proceeds from Sale, Maturity and Collection of Investments, Total | $ | | | | | | | | $ 10,000 | | |
Investment Sold, Shares (in shares) | shares | | | | | | | | 78,000 | | |
Truett-Hurst Common Stock [Member] | | | | | | | | | | |
Investment Owned, Balance, Shares (in shares) | shares | | | | | | | | | 10,000 | |
Proceeds from Sale, Maturity and Collection of Investments, Total | $ | | | | | | | | $ 30,000 | | |
Investment Sold, Shares (in shares) | shares | | | | | | | | 10,000 | | |
Arcimoto, Inc. Series A-1 Preferred Stock [Member] | | | | | | | | | | |
Investment Purchased, Shares (in shares) | shares | | | | | | | | | 37,000 | |
Payments to Acquire Investments, Total | $ | | | | | | | | | $ 100,011 | |
Options in Arcimoto, Inc [Member] | | | | | | | | | | |
Investment Owned, at Fair Value | $ | | | | | 55,848 | 55,848 | | | | |
Investment Owned, Balance, Shares (in shares) | shares | | | 2,500 | | | | 5,000 | | | |
Option Indexed to Issuer's Equity, Strike Price (in dollars per share) | $ / shares | | | $ 4.121 | | | | $ 2.0605 | | | |
Common Stock in Arcimoto, Inc [Member] | | | | | | | | | | |
Investment Owned, at Fair Value | $ | | | | | 489,510 | $ 489,510 | | | | |
Arcimoto, Inc. [Member] | | | | | | | | | | |
Gain (Loss) on Investments, Total | $ | | | | | $ 0 | | | | | |
Common Shares of Buoy Health, Inc [Member] | | | | | | | | | | |
Investment Purchased, Shares (in shares) | shares | 11,233 | | | | | | | | | |
Investment Purchased, Price Per Share (in dollars per share) | $ / shares | $ 15.92 | | | | | | | | | |
Investment Purchased, Value | $ | $ 178,824 | | | | | | | | | |