Note 7 - Share-based Compensation - Shared-based Compensation Expense and the Related Tax Benefit (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based compensation expense		$ 729	$ (35)	$ 1,790	$ 997
Related income tax benefit		78	67	207	192
Stock Options and SARs [Member]
Share-based compensation expense		412	108	921	286
Restricted Stock [Member]
Share-based compensation expense		203	215	566	612
Performance Shares [Member]
Share-based compensation expense	[1]	$ 114	$ (358)	$ 303	$ 99

[1] During the three and nine months ended September 30, 2019, the Company reversed $0.5 million of previously recognized expense for certain performance awards after determining that the performance conditions are not expected to be met.