Note 11 - Earnings Per Share Attributable to Common Stockholder - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities (in shares)	2,554,556	1,770,485	2,284,177
Service Period Stock Options [Member]
Antidilutive Securities (in shares)	1,355,590	1,500,156	2,018,050
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities (in shares)	190,006	235,847	213,591
Performance Stock Options [Member]
Antidilutive Securities (in shares)	1,008,960	34,482	52,536