Note 14 - Share-based Compensation - Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Balance, beginning of year, shares subject to option (in shares)	1,300,000	2,515,000
Balance, beginning of year, weighted average exercise price (in dollars per share)	$ 6.85	$ 6.55
Expired, shares subject to option (in shares)	(1,300,000)	(1,215,000)
Expired, weighted average exercise price (in dollars per share)	$ 6.85	$ 6.23
Balance, end of period, shares subject to option (in shares)		1,300,000
Balance, end of period, weighted average exercise price (in dollars per share)		$ 6.85
Options exercisable at end of period, shares subject to option (in shares)		1,300,000
Options exercisable at end of period, weighted average exercise price (in dollars per share)		$ 6.85