Note 6 - Financial Instruments and Fair Value (Details) - Investment in Auction Rate Securities - Fair Value (Auction Rate Securities [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Note 6 - Financial Instruments and Fair Value (Details) - Investment in Auction Rate Securities - Fair Value [Line Items]
Investment in auction rate securities	$ 6,812	$ 6,628
Fair Value, Inputs, Level 3 [Member]
Note 6 - Financial Instruments and Fair Value (Details) - Investment in Auction Rate Securities - Fair Value [Line Items]
Investment in auction rate securities	$ 6,812	$ 6,628

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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