Note 11 - Long-Term Debt Schedule of Convertible Debt (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term debt, net		$ 1,067,666		$ 1,067,666		$ 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		20,600		20,600		46,115
Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Equity component of currently redeemable convertible senior notes		13,100		13,100		75,100
Long-term debt, net		61,374		61,374		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]	(1,551)		(1,551)		(5,941)
Less: Debt issuance costs (1)	[1]	(82)		(82)		(314)
Long-term debt, net		20,600		20,600		46,115
Contractual interest expense of convertible debt		166	$ 456	705	$ 6,953
Amortization of debt issuance costs		17	43	71	659
Amortization of debt discount		322	808	1,344	11,910
Total interest expense for convertible debt		505	1,307	2,120	19,522
Convertible Debt | Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Principal amount of convertible debt in liabilities		68,024		68,024		389,992
Less: Debt discount, net (1)	[1]	(6,041)		(6,041)		(44,313)
Less: Debt issuance costs (1)	[1]	(609)		(609)		(4,465)
Long-term debt, net		61,374		61,374		$ 341,214
Contractual interest expense of convertible debt		493	2,250	3,043	6,750
Amortization of debt issuance costs		74	317	447	975
Amortization of debt discount		737	3,146	4,434	9,342
Total interest expense for convertible debt		$ 1,304	$ 5,713	$ 7,924	$ 17,067

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