Note 6 - Earnings (Loss) Per Share - Potentially Dilutive Securities Excluded from Diluted Net Income (Loss) per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Total antidilutive shares (in shares)	4,751	4,622	4,623	4,637
Share-based Payment Arrangement, Option [Member]
Total antidilutive shares (in shares)	51	16	27	50
Restricted Stock Units (RSUs) [Member]
Total antidilutive shares (in shares)	113	19	9	0
Convertible Debt Securities [Member]
Total antidilutive shares (in shares)	4,587	4,587	4,587	4,587