Consolidated Balance Sheets (Parentheticals) - $ / shares shares in Thousands	Dec. 31, 2020	Dec. 31, 2019
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000	5,000
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	450,000
Common stock, shares issued (in shares)	176,883	154,082
Common stock, shares outstanding (in shares)	176,883	154,082