Note 10 - Long-Term Debt Interest Expense Recognized Related to Convertible Debt (Details) (Convertible Debt [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Convertible Senior Notes Due 2017
Schedule of Interest Expense Recognized Related to Convertible Debt [Line Items]
Contractual interest expense of convertible debt	$ 3,375	$ 3,375
Amortization of debt issuance costs	318	300
Amortization of debt discount	5,708	5,186
Total interest expense for convertible debt	9,401	8,861
Debt Instrument, Interest Rate, Effective Percentage	9.75%	9.75%
Convertible Senior Notes Due 2019
Schedule of Interest Expense Recognized Related to Convertible Debt [Line Items]
Contractual interest expense of convertible debt	2,250	2,250
Amortization of debt issuance costs	328	316
Amortization of debt discount	3,073	2,889
Total interest expense for convertible debt	$ 5,651	$ 5,455
Debt Instrument, Interest Rate, Effective Percentage	6.25%	6.25%

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Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

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