Note 1 - General Information - Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net income (loss)	$ (8,245,000)	$ 14,199,000	$ (13,371,000)	$ 30,756,000
Undistributed income allocated to participating securities	0	0	0	0
Basic	(8,245,000)	14,199,000	(13,371,000)	30,756,000
Undistributed income allocated to participating securities	0	0	0	0
Undistributed income reallocated to participating securities	0	0	0	0
Diluted	$ (8,245,000)	$ 14,199,000	$ (13,371,000)	$ 30,756,000
Basic
Weighted-average common shares outstanding (in shares)	24,696,000	26,425,000	24,650,000	26,389,000
Dilutive effect of stock options and restricted stock awards (in shares)		8,000	0	7,000
Diluted (in shares)	24,696,000	26,433,000	24,650,000	26,396,000
Income (loss) per common share:
Basic (in dollars per share)	$ (0.33)	$ 0.54	$ (0.54)	$ 1.17
Diluted (in dollars per share)	$ (0.33)	$ 0.54	$ (0.54)	$ 1.17