Note 12 - Stockholders' Equity - Stock Options and SARs Outstanding by Exercise Price Range (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Outstanding, remaining contractual life (Year)	4 years 149 days	[1]
Outstanding, weighted average exercise price (in dollars per share)	$ 4.59
Exercisable (in shares) | shares	704
Exercisable, remaining contractual life (Year)	3 years 354 days
Exercisable, weighted average exercise price (in dollars per share)	$ 9.10
Outstanding (in shares) | shares	1,831
Restricted Stock Units (RSUs) [Member]
Range of exercise price, lower limit (in dollars per share)	$ 0
Range of exercise price, upper limit (in dollars per share)	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number, Ending Balance | shares	946
Options and SARs [Member] | Range 1 [Member]
Range of exercise price, lower limit (in dollars per share)	$ 5.21
Range of exercise price, upper limit (in dollars per share)	$ 7.26
Outstanding (in shares) | shares	157
Outstanding, remaining contractual life (Year)	2 years 76 days	[1]
Outstanding, weighted average exercise price (in dollars per share)	$ 5.94
Exercisable (in shares) | shares	157
Exercisable, remaining contractual life (Year)	2 years 76 days
Exercisable, weighted average exercise price (in dollars per share)	$ 5.94
Options and SARs [Member] | Range 2 [Member]
Range of exercise price, lower limit (in dollars per share)	7.49
Range of exercise price, upper limit (in dollars per share)	$ 9.71
Outstanding (in shares) | shares	276
Outstanding, remaining contractual life (Year)	4 years 18 days	[1]
Outstanding, weighted average exercise price (in dollars per share)	$ 8.82
Exercisable (in shares) | shares	276
Exercisable, remaining contractual life (Year)	4 years 18 days
Exercisable, weighted average exercise price (in dollars per share)	$ 8.82
Options and SARs [Member] | Range 3 [Member]
Range of exercise price, lower limit (in dollars per share)	10.15
Range of exercise price, upper limit (in dollars per share)	$ 15.79
Outstanding (in shares) | shares	452
Outstanding, remaining contractual life (Year)	5 years 142 days	[1]
Outstanding, weighted average exercise price (in dollars per share)	$ 11.16
Exercisable (in shares) | shares	271
Exercisable, remaining contractual life (Year)	4 years 328 days
Exercisable, weighted average exercise price (in dollars per share)	$ 11.22

[1] Calculation of weighted average remaining contractual term does not include the RSUs that were granted, which have an indefinite contractual term.