Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares issued (in shares)	61,987,799	60,996,367
Common stock, shares outstanding (in shares)	61,987,799	60,996,367
Series A Convertible Preferred Shares [Member]
Stockholders' equity:
Preferred stock, shares authorized (in shares)	300,000	300,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series B Convertible Preferred Shares [Member]
Stockholders' equity:
Preferred stock, shares authorized (in shares)	300,000	300,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0