Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	480,000,000	480,000,000
Common stock, shares issued (in shares)	117,800,000	117,300,000
Common stock, shares outstanding (in shares)	117,800,000	117,300,000
Treasury stock, shares (in shares)	249,742	137,860
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	900,000	900,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series A Convertible Preferred Stock [Member]
Temporary equity, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Temporary equity, shares issued (in shares)	65,507	58,197
Temporary equity, shares oustanding (in shares)	65,507	58,197
Series B Convertible Preferred Stock [Member]
Temporary equity, liquidation preference (in dollars per share)	$ 1,000	$ 1,000
Temporary equity, shares issued (in shares)	62,612	55,645
Temporary equity, shares oustanding (in shares)	62,612	55,645