Note 13 - Employee Benefits (Detail) - Stocks Options Outstanding by Grant Date (USD $)				0 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 08, 2003 Granted December 8, 2003 [Member]	May 12, 2004 Granted May 12, 2004 [Member]	Dec. 13, 2004 Granted December 13, 2004 [Member]	Dec. 14, 2005 Granted December 14, 2005 [Member]	Dec. 10, 2006 Granted December 10, 2006 [Member]	Apr. 19, 2007 Granted April 19, 2007 [Member]	May 16, 2007 Granted May 16, 2007 [Member]	Dec. 10, 2007 Granted December 10, 2007 [Member]	Jan. 02, 2008 Granted January 2, 2008 [Member]	Nov. 10, 2008 Granted November 10, 2008 [Member]	May 09, 2011 Granted May 19, 2011 [Member]
Exercise Price	$ 27.25	$ 26.81	$ 27.87	$ 24.29	$ 27.35	$ 30.45	$ 36.73	$ 40.24	$ 37.33	$ 37.48	$ 37.00	$ 36.25	$ 23.00	$ 17.55
Shares Outstanding (in Shares)	79,693	88,774	89,077	18,112	907	11,223	7,163	3,150	3,639	1,337	2,450	1,337	21,500	8,875
Contractual Average Life				343 days	1 year 120 days	1 year 346 days	2 years 346 days	3 years 346 days	4 years 113 days	4 years 149 days	4 years 346 days	5 years 43 days	5 years 346 days	8 years 149 days
Average Exercise Price	$ 27.25	$ 26.81	$ 27.87	$ 24.29	$ 27.35	$ 30.45	$ 36.73	$ 40.24	$ 37.33	$ 37.48	$ 37.00	$ 36.25	$ 23.00	$ 17.55
Shares Exercisable (in Shares)	79,693	79,774		18,112	907	11,223	7,163	3,150	3,639	1,337	2,450	1,337	21,500	8,875
Average Exercise Price	$ 27.25	$ 27.85		$ 24.29	$ 27.35	$ 30.45	$ 36.73	$ 40.24	$ 37.73	$ 37.48	$ 37.00	$ 36.25	$ 23.00	$ 17.55

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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