Note 11 - Employee Benefits (Details) (USD $)	12 Months Ended					1 Months Ended				12 Months Ended			12 Months Ended						12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Employee Stock Option [Member] 2005 Plan [Member]	Dec. 31, 2013 Performance Shares [Member] 2005 Plan [Member]	May 31, 2013 Performance Shares [Member]	May 31, 2012 Performance Shares [Member]	Aug. 30, 2011 Performance Shares [Member]	Aug. 30, 2010 Performance Shares [Member]	Dec. 31, 2013 Performance Shares [Member]	Dec. 31, 2013 Unvested Service-Based Option Awards [Member]	Dec. 31, 2013 Unvested Performance Unit Awards [Member]	Dec. 31, 2013 Service-Based Options [Member]	Dec. 31, 2012 Service-Based Options [Member]	Dec. 31, 2011 Service-Based Options [Member]	Dec. 31, 2013 Participants Less Than 50 Years Old [Member]	Dec. 31, 2013 Participants Over 50 Years Old [Member]	Dec. 31, 2013 2005 Plan [Member]	Dec. 31, 2013 2005 Plan [Member] Minimum [Member]	Dec. 31, 2013 2005 Plan [Member] Maximum [Member]
Note 11 - Employee Benefits (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period																			7 years	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period				1 year	5 years				5 years
Share-Based Compensation Arrangement by Share-Based Payment Award, Annual Percentage of Award Which Vests				20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)																		2,850,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Reserved For Issuance Under Awards Outstanding (in Shares)				1,015,759	197,163
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted (in Shares)						62,550	59,250	62,400	95,100
Share-based Compensation Arrangement by Share-Based Payment Awards, Annual Service Vesting Percentage									5.00%
Average Annual Earnings Percentage Increase, Goal of Share-Based Compensation Awards									15.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Forfeiture Rate of Unvested Outstanding Awards	1.25%
Allocated Share-based Compensation Expense	$ 1,084,000	$ 1,225,000	$ 1,349,000
Allocated Share-based Compensation Expense, Net of Tax	672,000	759,000	837,000
Allocated Share-based Compensation Expense, Net of Tax, Amount Per Basic And Diluted Share (in Dollars per share)	$ 0.02	$ 0.023	$ 0.025
Excess Tax Benefit from Share-based Compensation, Financing Activities	165,000	336,000	142,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized											1,600,000	1,400,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition											3 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number (in Shares)	1,015,759	995,046
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	6,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in Shares)	684,309
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	3 years 109 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	4,600,000
Stock Granted, Value, Share-based Compensation, Gross													953,000	695,000	350,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	915,000	1,400,000	442,000
Proceeds from Stock Options Exercised	1,100,000	968,000	137,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	636,000	751,000	856,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value										491,000
Defined Contribution Plan, Maximum Statutory Contribution Amount Allowed By Each Plan Participant																17,500	23,000
Defined Contribution Plan, Percentage of Participant's Contribution Matched By Employer	35.00%
Defined Contribution Plan, Max Percentage of Participant's Contributions Matched By Employer	6.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	20.00%
Defined Contribution Plan, Cost Recognized	$ 1,400,000	$ 909,000	$ 803,000