Note 11 - Share-based Compensation - Stock-settled Stock Appreciation Rights Transactions (Details) - Stock Appreciation Rights (SARs) [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Outstanding SARS (in shares)	206,700
Outstanding SARS, weighted average exercise price (in dollars per share)	$ 18.67
Outstanding SARS, weighted average remaining life (Year)	3 years 4 months 9 days	2 years 14 days
Outstanding SARS, aggregate intrinsic value	$ 2,031	$ 0
Granted SARs (in shares)	225,625
Granted SARS, weighted average exercise price (in dollars per share)	$ 10.08
Exercised SARs (in shares)	(46,696)
Exercised SARS, weighted average exercise price (in dollars per share)	$ 16.46
Lapsed or cancelled (in shares)	(68,501)
Lapsed or cancelled, weighted average exercise price (in dollars per share)	$ 15.97
Outstanding SARS (in shares)	317,128	206,700
Outstanding SARS, weighted average exercise price (in dollars per share)	$ 13.47	$ 18.67
Exercisable (in shares)	79,372
Exercisable, weighted average exercise price (in dollars per share)	$ 20.42
Exercisable, weighted average remaining life (Year)	1 year 6 months 21 days
Exercisable, aggregate intrinsic value	$ 238