Note 1 - General Information (Details) - Earnings Per Share (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Net income attributable to common stockholders	$ 9,856	$ 14,064	$ 12,727	$ 11,155
Undistributed income allocated to participating securities		(28)		(46)
Basic	9,856	14,036	12,727	11,109
Undistributed income allocated to participating securities		28		46
Undistributed income reallocated to participating securities		(28)		(46)
Diluted	$ 9,856	$ 14,036	$ 12,727	$ 11,109
Weighted-average common shares outstanding (in Shares)	26,120	26,243	26,082	26,120
Dilutive effect of stock options and restricted stock awards (in Shares)	8	18	7	36
Diluted (in Shares)	26,128	26,261	26,089	26,155
Basic (in Dollars per share)	$ 0.38	$ 0.53	$ 0.49	$ 0.43
Diluted (in Dollars per share)	$ 0.38	$ 0.53	$ 0.49	$ 0.42