Note 4 - Earnings Per Share (Details) - Earnings Per Share Calculation (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Numerator for basic and diluted earnings per share-
Net income available to common shareholders (in Dollars)	$ 12,014	$ 13,547
Denominator-
Denominator for basic earnings per share, weighted average shares outstanding	39,332	39,119
Effect of dilutive securities-
Employee and Director stock options and restricted stock awards	1,179	1,150
Denominator for diluted earnings per share, adjusted weighted average shares and assumed conversions	40,511	40,269
Basic earnings per common share (in Dollars per share)	$ 0.31	$ 0.35
Diluted earnings per common share and common share equivalents (in Dollars per share)	$ 0.30	$ 0.34