Note 7 - Share-based Compensation - Stock-settled Stock Appreciation Rights Transactions (Details) - Stock Appreciation Rights (SARs) [Member] - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 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 5 months 15 days	2 years 14 days
Outstanding SARS, aggregate intrinsic value		$ 316	$ 0
Granted SARs (in shares)	[1]	225,625
Granted SARS, weighted average exercise price (in dollars per share)	[1]	$ 10.08
Exercised SARs (in shares)		0
Exercised SARS, weighted average exercise price (in dollars per share)		$ 0
Lapsed or cancelled (in shares)		(68,501)
Lapsed or cancelled, weighted average exercise price (in dollars per share)		$ 15.97
Outstanding SARS (in shares)		363,824	206,700
Outstanding SARS, weighted average exercise price (in dollars per share)		$ 13.85	$ 18.67
Exercisable (in shares)		126,068
Exercisable, weighted average exercise price (in dollars per share)		$ 18.95
Exercisable, weighted average remaining life (Year)		1 year 6 months 29 days
Exercisable, aggregate intrinsic value		$ 0

[1] The weighted average grant date fair value of SARs granted was $2.14 per share.