Note 13 - Stock-based Compensation - Stock Option Transactions (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Outstanding, option shares (in shares)	10,541
Outstanding, weighted average exercise price (in dollars per share)	$ 16.63
Granted, option shares (in shares)	0	0	0
Granted, weighted average exercise price (in dollars per share)	$ 0
Exercised, option shares (in shares)	(5,346)	(2,573)	(37,104)
Exercised, weighted average exercise price (in dollars per share)	$ 16.63
Forfeited, option shares (in shares)	(332)
Forfeited, weighted average exercise price (in dollars per share)	$ 16.63
Expired, option shares (in shares)	0
Expired, weighted average exercise price (in dollars per share)	$ 0
Outstanding, option shares (in shares)	4,863	10,541
Outstanding, weighted average exercise price (in dollars per share)	$ 16.63	$ 16.63
Outstanding, Weighted Average Remaining Contractual Term (Year)	2 years 11 months 19 days
Outstanding, Aggregate Intrinsic Value	$ 102
Exercisable, option shares (in shares)	4,863
Exercisable, weighted average exercise price (in dollars per share)	$ 16.63
Exercisable, Weighted Average Remaining Contractual Term (Year)	2 years 11 months 19 days
Exercisable, Aggregate Intrinsic Value	$ 102