Note 3 - Earnings Per Share (Details) - Earnings Per Common Share: (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Earnings Per Common Share: [Abstract]
Net income, as reported (in Dollars)	$ 11,685		$ 9,627		$ 21,981		$ 16,383
Divided by:
Weighted average common shares outstanding	30,059		30,213		30,022		30,330
Weighted average common stock equivalents	31		22		34		27
Total weighted average common shares outstanding and common stock equivalents	30,090		30,235		30,056		30,357
Basic earnings per common share (in Dollars per share)	$ 0.39		$ 0.32		$ 0.73		$ 0.54
Diluted earnings per common share (1) (in Dollars per share)	$ 0.39	[1]	$ 0.32	[1]	$ 0.73	[1]	$ 0.54	[1]
Dividend payout ratio	38.50%		40.60%		41.10%		48.10%

[1] For the three and six months ended June 30, 2014, there were no options which were considered anti-dilutive. For the three and six months ended June 30, 2013, options to purchase 542,340 shares at an average exercise price of $17.66 were not included in the computation of diluted earnings per common share as they were anti-dilutive.