Note 9 - Share Capital (Details Textual) - USD ($) $ in Thousands		3 Months Ended	4 Months Ended	12 Months Ended
	Jun. 18, 2019	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)		16,564		394,078
Stock Issued During Period, Shares, Restricted Stock Award, Gross (in shares)		40,109		65,405
Stock Repurchase Program, Authorized Amount			$ 100,000	$ 100,000
Stock Repurchased During Period, Shares (in shares)		530,890	478,856
Stock Repurchased During Period, Value		$ 7,732	$ 7,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 100,000	$ 85,300
Stock Repurchase Program, Period in Force (Year)	5 years