Note 4 - Earnings Per Share (Details) - Basic and Diluted Earnings Per Share (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator:
Numerator for basic and diluted earnings per share – Net income available to common shareholders (in Dollars)	$ 15,179	$ 14,909	$ 34,358	$ 48,237
Denominator–
Denominator for basic earnings per share – weighted average shares outstanding	39,558	38,740	39,411	38,602
Effect of dilutive securities–
Employee and director stock options and restricted share awards	1,065	862	1,081	1,031
Denominator for diluted earnings per share – adjusted weighted average shares outstanding and assumed conversions	40,623	39,602	40,492	39,633
Basic earnings per common share (in Dollars per share)	$ 0.38	$ 0.38	$ 0.87	$ 1.25
Diluted earnings per common share and common share equivalents (in Dollars per share)	$ 0.37	$ 0.38	$ 0.85	$ 1.22