Number of equity instruments other than options exercised by participants during the period.

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+ References

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Gross number of share options (or share units) granted during the period.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Amount of cost expensed and capitalized for award under share-based payment arrangement.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Note 10 - Equity Incentive Plans and Equity (Details Textual) - USD ($) $ / shares in Units, Pure in Thousands, $ in Millions	1 Months Ended		3 Months Ended	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2016	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2016	Nov. 30, 2014	Dec. 31, 2012	Dec. 31, 2010
Share-based Payment Arrangement, Expense				$ 10.9	$ 7.8	$ 6.8
Share-based Payment Arrangement, Expensed and Capitalized, Amount, Total				$ 0.2	$ 0.2
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)				$ 68.93	$ 24.24	$ 14.27
Executive Vice President [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)				3 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			15,000
Service Period Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)				874,153
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)				382,910
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value				$ 48.8	$ 18.4	$ 7.3
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount				$ 24.7
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)				$ 64.75
Service Period Stock Options [Member] \| Share-based Payment Arrangement, Tranche One [Member]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount				$ 5.9
Service Period Stock Options [Member] \| Share-based Payment Arrangement, Tranche Two [Member]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount				5.7
Service Period Stock Options [Member] \| Share-based Payment Arrangement, Tranche Three [Member]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount				4.9
Service Period Stock Options [Member] \| Share-based Payment Arrangement, Tranche Four [Member]
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount				$ 8.2
Service Period Stock Options [Member] \| Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)				4 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)							500,000
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate				0.00%	0.00%	0.00%
Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 4.0
Restricted Stock Units (RSUs) [Member] \| Share-based Payment Arrangement, Tranche One [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				2.6
Restricted Stock Units (RSUs) [Member] \| Share-based Payment Arrangement, Tranche Two [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				1.2
Restricted Stock Units (RSUs) [Member] \| Share-based Payment Arrangement, Tranche Three [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 0.2
Performance Stock Options [Member] \| Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)							500,000
Performance Stock Options With Probable Vesting Criteria [Member]
Unrecognized Compensation Costs, Performance Based Awards (in shares)				861,047
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 44.2
Performance Stock Options With Probable Vesting Criteria [Member] \| Share-based Payment Arrangement, Tranche One [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				12.5
Performance Stock Options With Probable Vesting Criteria [Member] \| Share-based Payment Arrangement, Tranche Two [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				11.8
Performance Stock Options With Probable Vesting Criteria [Member] \| Share-based Payment Arrangement, Tranche Three [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				10.3
Performance Stock Options With Probable Vesting Criteria [Member] \| Share-based Payment Arrangement, Tranche Four [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 9.6
Performance Stock Options Deemed Not Probable To Vest [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Exercises in Period (in shares)				248,999
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value				$ 18.2
Performance Based Restricted Stock Units [Member]
Unrecognized Compensation Costs, Performance Based Awards (in shares)				22,894
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 2.4
Performance Based Restricted Stock Units [Member] \| Share-based Payment Arrangement, Tranche One [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				0.8
Performance Based Restricted Stock Units [Member] \| Share-based Payment Arrangement, Tranche Two [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				0.8
Performance Based Restricted Stock Units [Member] \| Share-based Payment Arrangement, Tranche Three [Member]
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount				$ 0.8
The 2010 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)									2,220,280	2,146,320
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in shares)				26,130
The 2010 Stock Plan [Member] \| Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)				10 years
Stock Plan 2010 [Member] \| Service Period Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)				4 years
Omnibus Incentive Plan 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares)		3,979,200		2,610,490				1,479,200
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares)	700,000	2,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)	4,679,200
Common Stock, Capital Shares Reserved for Future Issuance (in shares)				908,433
Omnibus Incentive Plan 2014 [Member] \| Service Period Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)				3 years
Omnibus Incentive Plan 2014 [Member] \| Service Period Stock Options [Member] \| Share-based Payment Arrangement, Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)				3 years
Omnibus Incentive Plan 2014 [Member] \| Restricted Stock Units (RSUs) [Member] \| Share-based Payment Arrangement, Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)				1 year
Cost of Sales [Member]
Share-based Payment Arrangement, Expense				$ 2.1	$ 0.9	$ 0.9
Selling, General and Administrative Expenses [Member]
Share-based Payment Arrangement, Expense				$ 8.8	$ 6.9	$ 5.9