Consolidated Balance Sheets (Parentheticals) - USD ($)
Dec. 31, 2021
Dec. 31, 2020
Accounts receivable, allowance $ 1,993 $ 2,077
Preferred stock, par value (in dollars per share) $ 0.01 $ 0.01
Preferred stock, shares authorized (in shares) 50,000,000 50,000,000
Preferred stock, shares issued (in shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, shares authorized (in shares) 450,000,000 450,000,000
Common stock, shares issued (in shares) 36,943,770 36,494,002
Common stock, shares outstanding (in shares) 36,943,770 36,494,002