Condensed Consolidated Balance Sheets (Parentheticals) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, reserve	$ 2,325,589	$ 2,472,345
Vessels and vessel improvements, accumulated depreciation	177,765,956	153,029,544
Other fixed assets, accumulated depreciation	$ 1,067,000	$ 832,541
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	700,000,000	700,000,000
Common stock, shares issued (in shares)	10,279,698	10,214,600
Common stock outstanding (in shares)	10,279,698	10,214,600