Note 3 - Long-Term Debt (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Special Dividend [Member]	Dec. 31, 2012 Credit Facility [Member]	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]
Note 3 - Long-Term Debt (Details) [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						$ 50,000,000	$ 75,000,000
Line of Credit Facility, Amount Outstanding	0	2,700,000
Letters of Credit Outstanding, Amount	8,300,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 41,700,000
Long-term Debt, Weighted Average Interest Rate					1.05%
Line of Credit Facility, Dividend Restrictions, Percentage of Net Income Limit	25.00%
Common Stock, Dividends, Per Share, Cash Paid (in Dollars per share)	$ 0.083	$ 0.563	$ 0.053	$ 0.50