Note 3 - Marketable Securities (Details) - Fair Value, Financial Assets Measured by Level within The Fair Value Hierarchy (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Note 3 - Marketable Securities (Details) - Fair Value, Financial Assets Measured by Level within The Fair Value Hierarchy [Line Items]
Cost	$ 3,965	$ 5,119
Unrealized Gain	1	2
Estimated Fair Value	3,966	5,121
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 3 - Marketable Securities (Details) - Fair Value, Financial Assets Measured by Level within The Fair Value Hierarchy [Line Items]
Cost	403	455
Unrealized Gain		1
Estimated Fair Value	403	456
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 3 - Marketable Securities (Details) - Fair Value, Financial Assets Measured by Level within The Fair Value Hierarchy [Line Items]
Cost	162	164
Unrealized Gain	1	1
Estimated Fair Value	163	165
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 3 - Marketable Securities (Details) - Fair Value, Financial Assets Measured by Level within The Fair Value Hierarchy [Line Items]
Cost	3,400	4,500
Unrealized Gain	0	0
Estimated Fair Value	$ 3,400	$ 4,500