Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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- Definition

Nominal or face amount used to calculate payments on the derivative liability.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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- Definition

Nominal or face amount used to calculate payment on derivative.

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- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of open derivatives, commodity, or energy contracts, held at each balance sheet date, that was included in earnings for the period.

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Note 9 - Fair Value Measurement (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Jan. 01, 2021	Dec. 31, 2020	Nov. 30, 2020	Mar. 31, 2020	May 31, 2018
Derivative Liability, Notional Amount						$ 150.0
The 2.75% Convertible Notes [Member]
Debt Instrument, Interest Rate, Stated Percentage	2.75%		2.75%		2.75%
Debt Instrument, Convertible, Carrying Amount of Equity Component	$ 28.0		$ 29.7		$ 34.7
Commodity Contract [Member]
Derivative, Notional Amount	2.6	$ 3.1		$ 3.5
Unrealized Gain (Loss) on Derivatives and Commodity Contracts, Total	$ 1.0
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	2.76%