Note 2 - Summary of Significant Accounting Policies (Details) - Earnings Per Common Share: (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Common Share: [Abstract]
Net income, as reported (in Dollars)	$ 11,948	$ 9,421	$ 9,627	$ 6,756	$ 9,200	$ 9,365	$ 8,637	$ 7,129	$ 37,752	$ 34,331	$ 35,348
Divided by:
Weighted average common shares outstanding	29,762	29,773	30,213	30,449	30,310	30,432	30,472	30,396	30,047	30,402	30,623
Weighted average common stock equivalents									26	31	31
Total weighted average common shares outstanding and common stock equivalents	29,802	29,805	30,235	30,481	30,340	30,462	30,492	30,420	30,073	30,433	30,654
Basic earnings per common share (in Dollars per share)	$ 0.40	$ 0.32	$ 0.32	$ 0.22	$ 0.30	$ 0.31	$ 0.28	$ 0.23	$ 1.26	$ 1.13	$ 1.15
Diluted earnings per common share (in Dollars per share)	$ 0.40	$ 0.32	$ 0.32	$ 0.22	$ 0.30	$ 0.31	$ 0.28	$ 0.23	$ 1.26	$ 1.13	$ 1.15