Note 10 - Long-Term Debt Interest Expense Recognized Related to Convertible Debt (Details) - Convertible Debt [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Convertible Senior Notes Due 2017
Schedule of Interest Expense Recognized Related to Convertible Debt [Line Items]
Contractual interest expense of convertible debt	$ 372	$ 3,375
Amortization of debt issuance costs	37	318
Amortization of debt discount	708	5,708
Total interest expense for convertible debt	1,117	9,401
Convertible Senior Notes Due 2019
Schedule of Interest Expense Recognized Related to Convertible Debt [Line Items]
Contractual interest expense of convertible debt	2,013	2,250
Amortization of debt issuance costs	293	328
Amortization of debt discount	2,909	3,073
Total interest expense for convertible debt	$ 5,215	$ 5,651