Note 11 - Long-Term Debt Schedule of Convertible Debt (Details) - USD ($) $ in Thousands			3 Months Ended			9 Months Ended
		Jan. 27, 2017	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Net carrying amount			$ 1,026,806			$ 1,026,806		$ 1,069,537
Convertible Senior Notes Due 2017
Debt Instrument [Line Items]
Repayments of Convertible Debt				$ 31,600
Debt Instrument, Convertible, Carrying Amount of Equity Component			100			100		5,000
Net carrying amount			521			521		20,947
Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Repayments of Convertible Debt		$ 110,100
Debt Instrument, Convertible, Carrying Amount of Equity Component								13,100
Net carrying amount			0			0		62,013
Convertible Debt | Convertible Senior Notes Due 2017
Debt Instrument [Line Items]
Principal amount of convertible debt in liabilities			526			526		22,233
Less: Debt discount, net (1)	[1]		(5)			(5)		(1,221)
Less: Debt issuance costs (1)	[1]		0			0		(65)
Net carrying amount			521			521		20,947
Contractual interest expense (benefit)	[2]		4		$ 166	312	$ 705
Amortization of debt issuance costs			0		17	32	71
Amortization of debt discount			10		322	615	1,344
Total interest expense (benefit)	[2]		14		505	959	2,120
Convertible Debt | Convertible Senior Notes Due 2019
Debt Instrument [Line Items]
Principal amount of convertible debt in liabilities			0			0		68,024
Less: Debt discount, net (1)	[1]		0			0		(5,461)
Less: Debt issuance costs (1)	[1]		0			0		(550)
Net carrying amount			0			0		$ 62,013
Contractual interest expense (benefit)	[3]		0		493	(510)	3,043
Amortization of debt issuance costs			0		74	16	447
Amortization of debt discount			0		737	163	4,434
Total interest expense (benefit)	[3]		$ 0		$ 1,304	$ (331)	$ 7,924

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

[2] Interest expense (benefit) represents expense incurred, net of adjustments to accruals previously recorded.

[3] Interest expense (benefit) represents expense incurred, net of adjustments to accruals previously recorded.