Note 6 - Stockholders' Equity (Detail) (USD $)	3 Months Ended	12 Months Ended								12 Months Ended		3 Months Ended	12 Months Ended		24 Months Ended	12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 The 2011 Non-Employee Director Plan [Member]	Dec. 31, 2012 The 2006 Non-Employee Director Plan [Member]	Dec. 31, 2012 The 2001 Non-Employee Director Equity Incentive Plan [Member]	Dec. 31, 2008 Performance-Based Award [Member] Joseph Burgess Compensation [Member]	Dec. 31, 2008 Appointment Award [Member] Joseph Burgess Compensation [Member]	Mar. 31, 2012 Open Market Repurchases [Member]	Dec. 31, 2012 Open Market Repurchases [Member]	Dec. 31, 2011 Open Market Repurchases [Member]	Dec. 31, 2012 Open Market Repurchases [Member]	Dec. 31, 2012 In Connection With Compensation Programs [Member]	Dec. 31, 2012 The 2009 Employee Plan [Member]	Dec. 31, 2012 The 2006 Employee Plan [Member]	Dec. 31, 2012 The 2001 Employee Equity Incentive Plan [Member]	Dec. 31, 2008 Joseph Burgess Compensation [Member]	Dec. 31, 2012 Joseph Burgess Compensation [Member]
Stock Repurchase Program, Authorized Amount (in Dollars)	$ 5,000,000	$ 5,000,000											$ 5,000,000	$ 5,000,000	$ 10,000,000	$ 5,000,000
Stock Repurchased and Retired During Period, Shares	272,790		90,147									310,035
Stock Repurchased and Retired During Period, Value (in Dollars)	5,000,000		1,600,000									5,000,000
Treasury Stock Acquired, Average Cost Per Share (in Dollars per share)	$ 18.33		$ 18.15									$ 16.13
Stock Issued During Period, Shares, Other			5,577
Stock Issued During Period, Value, Other (in Dollars)			$ 37,600
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized							200,000										2,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	1,216,809		1,216,809	1,107,712	1,198,516	1,167,640											643,261	448,001	7,150		118,397
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number							47,371	66,847	67,300								590,475	5,302			103,092
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures																				118,397
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period										52,784	103,092