Note 15 - Fair Value Measurements and Disclosures (Details) (USD $)	Jan. 31, 2011	Dec. 31, 2014		Dec. 31, 2013		Sep. 30, 2013	May 31, 2013	Jul. 31, 2011	Mar. 31, 2010
Note 15 - Fair Value Measurements and Disclosures (Details) [Line Items]
Debt Instrument, Face Amount	$ 40,000,000
Fair Value, Inputs, Level 1 [Member] | Convertible Notes 2017 [Member]
Note 15 - Fair Value Measurements and Disclosures (Details) [Line Items]
Convertible Debt, Fair Value Disclosures		57,400,000		130,100,000
Fair Value, Inputs, Level 1 [Member] | Convertible Notes 2015 [Member]
Note 15 - Fair Value Measurements and Disclosures (Details) [Line Items]
Convertible Debt, Fair Value Disclosures		20,700,000		79,700,000
$40 Million Secured Debt Facility [Member]
Note 15 - Fair Value Measurements and Disclosures (Details) [Line Items]
Debt Instrument, Face Amount	40,000,000					40,000,000	25,500,000
$75 Million Secured Debt Facility [Member]
Note 15 - Fair Value Measurements and Disclosures (Details) [Line Items]
Debt Instrument, Face Amount							75,000,000	75,000,000
Convertible Notes 2017 [Member]
Note 15 - Fair Value Measurements and Disclosures (Details) [Line Items]
Convertible Debt, Fair Value Disclosures		57,361,000	[1]	130,094,000	[1]	124,500,000
Convertible Notes 2015 [Member]
Note 15 - Fair Value Measurements and Disclosures (Details) [Line Items]
Convertible Debt, Fair Value Disclosures		$ 20,662,000	[2]	$ 79,663,000	[2]				$ 136,300,000

[1] The Company estimated the fair value of the 2017 Convertible Notes to be approximately $57.4 million and $130.1 million at December 31, 2014 and December 31, 2013, respectively, based on observed market prices for the same or similar types of debt issues. The fair value of the 2017 Convertible Notes is considered to be a Level 1 measurement on the fair value hierarchy.

[2] The Company estimated the fair value of the 2015 Convertible Notes to be approximately $20.7 million and $79.7 million at December 31, 2014 and December 31, 2013, respectively, based on observed market prices for the same or similar types of debt issues. The fair value of the 2015 Convertible Notes is considered to be a Level 1 measurement on the fair value hierarchy.