Note 11 - Long-Term Debt Schedule of Convertible Debt (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term debt, net		$ 1,278,051		$ 1,278,051		$ 1,219,454
Convertible Senior Notes Due 2017
Debt Instrument [Line Items]
Equity component of currently redeemable convertible senior notes		5,000		5,000		11,300
Long-term debt, net		20,261		20,261		46,115
Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Equity component of currently redeemable convertible senior notes		17,200		17,200		75,100
Long-term debt, net		79,649		79,649		341,214
Convertible Debt | Convertible Senior Notes Due 2017
Debt Instrument [Line Items]
Principal amount of convertible debt in liabilities		22,233		22,233		52,370
Less: Debt discount, net (1)	[1]	(1,873)		(1,873)		(5,941)
Less: Debt issuance costs (1)	[1]	(99)		(99)		(314)
Long-term debt, net		20,261		20,261		46,115
Contractual interest expense of convertible debt		167	$ 3,122	539	$ 6,497
Amortization of debt issuance costs		17	298	54	616
Amortization of debt discount		314	5,394	1,022	11,102
Total interest expense for convertible debt		498	8,814	1,615	18,215
Convertible Debt | Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Principal amount of convertible debt in liabilities		89,194		89,194		389,992
Less: Debt discount, net (1)	[1]	(8,671)		(8,671)		(44,313)
Less: Debt issuance costs (1)	[1]	(874)		(874)		(4,465)
Long-term debt, net		79,649		79,649		$ 341,214
Contractual interest expense of convertible debt		537	2,250	2,550	4,500
Amortization of debt issuance costs		80	330	373	658
Amortization of debt discount		788	3,123	3,697	6,196
Total interest expense for convertible debt		$ 1,405	$ 5,703	$ 6,620	$ 11,354

[1] Included within long-term debt and is being amortized over the life of the convertible notes.