Note 9 - Share Capital (Details Textual) - USD ($) $ in Thousands		3 Months Ended				4 Months Ended	9 Months Ended	12 Months Ended
	Jun. 18, 2019	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Dec. 31, 2019	Sep. 30, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)							27,616	394,078
Stock Issued During Period, Shares, Restricted Stock Award, Gross (in shares)							45,130	65,405
Stock Repurchase Program, Authorized Amount						$ 100,000		$ 100,000
Stock Repurchased During Period, Shares (in shares)		0	0	530,890		478,856
Stock Repurchased During Period, Value				$ 7,732	$ 3,325	$ 7,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 85,300					$ 85,300
Stock Repurchase Program, Period in Force (Year)	5 years