Note 8 - Equity Plans (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended				0 Months Ended	6 Months Ended	12 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jan. 02, 2013	Jan. 03, 2012	Jan. 02, 2013 Restricted Stock Units (RSUs) [Member]	Jun. 30, 2013 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2011 Purchase Requirement [Member]	Dec. 31, 2011 Matching Purchase Requirement [Member]	Dec. 31, 2011 Match [Member]	Jun. 30, 2013 Five Year Anniversary [Member]	Jun. 30, 2013 Ten Year Anniversary [Member]	Jun. 30, 2013 Fifteen Year Anniversary [Member]	Jun. 30, 2013 Twenty Year Anniversary [Member]	Jun. 30, 2013 Twenty Five Year Anniversary [Member]
Note 8 - Equity Plans (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	1,667	2,170
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value (in Dollars)	$ 28	$ 52
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	500,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period					1,800	37,341
Share Price (in Dollars per share)			$ 23.41	$ 25.55
Share-based Compensation Arrangement by Share-based Payment Award, Description							750	500	250
Shares Matched	6,500	6,750
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Intrinsic Value, Amount Per Share (in Dollars per share)										$ 25,000	$ 50,000	$ 75,000	$ 100,000	$ 100,000
Restricted Stock Units, Units, Number Converted		375