Note 6 - Financial Instruments and Fair Value (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Mar. 31, 2014	Mar. 31, 2014 Cash Flow Hedging [Member] Interest Rate Swap [Member]	Mar. 31, 2014 Auction Rate Securities [Member]	Dec. 31, 2013 Auction Rate Securities [Member]	Mar. 31, 2013 Auction Rate Securities [Member]
Note 6 - Financial Instruments and Fair Value (Details) [Line Items]
Available-for-sale Securities				$ 6,628,000	$ 6,628,000	$ 6,600,000
Available-for-sale Securities, Amortized Cost Basis				7,575,000	7,575,000	7,600,000
Derivative, Basis Spread on Variable Rate				2.25%
Asset Impairment Charges	1,000,000
Derivative Asset, Notional Amount			37,500,000
Interest Rate Cash Flow Hedge Liability at Fair Value		$ 800,000