Note 4 - Earnings per Share (Details) - Earnings per Share - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Note 4 - Earnings per Share (Details) - Earnings per Share [Line Items]
Net income (in Dollars)	$ 45,200	$ 35,084	$ 81,180	$ 66,343
Weighted-average shares:
Basic weighted-average number of common shares outstanding	79,939,197	79,642,993	79,887,699	79,619,506
Dilutive effect of weighted-average outstanding common share equivalents
Diluted weighted-average number of common shares outstanding	80,698,994	80,046,471	80,505,265	80,042,946
Average stock options and warrants with anti-dilutive effect	939,615	2,003,896	1,246,123	1,994,922
Earnings per common share:
Basic (in Dollars per share)	$ 0.57	$ 0.44	$ 1.02	$ 0.83
Diluted (in Dollars per share)	$ 0.56	$ 0.44	$ 1.01	$ 0.83
Warrant [Member]
Dilutive effect of weighted-average outstanding common share equivalents
Dilutive effect of weighted-average outstanding common share equivalents	566,405	273,759	456,274	286,079
Equity Option [Member]
Dilutive effect of weighted-average outstanding common share equivalents
Dilutive effect of weighted-average outstanding common share equivalents	139,867	97,476	124,249	99,575
Restricted Stock Units (RSUs) [Member]
Dilutive effect of weighted-average outstanding common share equivalents
Dilutive effect of weighted-average outstanding common share equivalents	53,525	32,243	37,043	37,786