Note 10 - Stock Incentive Plans - Summary of Activity for Restricted Stock Units, Long-term Incentive Awards and Non-employee Director Stock Compensation (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	6 Months Ended
	Jun. 30, 2018 $ / shares shares
Number of shares - Nonvested (in shares) | shares	1,223
Weighted average grant date fair value - Nonvested (in dollars per share) | $ / shares	$ 2
Number of shares - Granted (in shares) | shares	335
Weighted average grant date fair value - Granted (in dollars per share) | $ / shares	$ 1.76
Number of shares - Vested (in shares) | shares	(677)
Weighted average grant date fair value - Vested (in dollars per share) | $ / shares	$ 1.92
Number of shares - Canceled or expired (in shares) | shares	(42)
Weighted average grant date fair value - Canceled or expired (in dollars per share) | $ / shares	$ 1.87
Number of shares - Nonvested (in shares) | shares	839
Weighted average grant date fair value - Nonvested (in dollars per share) | $ / shares	$ 1.97