Note 15 - Fair Value Measurements and Disclosures (Details) - Fair Value of Company’s Fixed Rate Debt (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Sep. 30, 2013	Mar. 31, 2010
Convertible Notes 2017 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	$ 154,839	[1]	$ 125,416	[1]
Fair Value	57,361	[1]	130,094	[1]	124,500
Convertible Notes 2015 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying Amount	59,473	[2]	81,523	[2]
Fair Value	$ 20,662	[2]	$ 79,663	[2]		$ 136,300

[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.