Note 10 - Long-term Obligations - Schedule of Data Regarding the 6.25% Notes (Details) - 6.25% Convertible Notes Due 2018 [Member] - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2018	Mar. 28, 2017
Net carrying amount of the equity component	$ 686
Convertible notes	10,044		$ 94,000
Unamortized debt discount	$ 18
Amortization period remaining (months) (Month)	120 days
Net carrying amount of the convertible notes	$ 10,026

Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

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Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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