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Note 8 - Derivative Instruments and Hedging Activities (Details Textual) $ in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 CAD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 CAD ($)
Foreign Exchange Forward [Member]
Unrealized Loss on Foreign Currency Derivatives, before Tax			$ 0.2
Foreign Exchange Forward [Member] | Maximum [Member]
Maturity Period For Forward Contracts (Month)	12 months
Three Foreign Exchange Forwards [Member]
Derivative, Notional Amount	$ 10.9		$ 10.9		$ 14.9
Three Foreign Exchange Forwards [Member] | Maximum [Member]
Derivative, Remaining Maturity (Month)			23 months
Three Foreign Exchange Forwards [Member] | Minimum [Member]
Derivative, Remaining Maturity (Month)			18 months
Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivative, Notional Amount	15.0		$ 15.0		$ 20.4	$ 6.1	$ 7.9
Not Designated as Hedging Instrument [Member] | Foreign Exchange Forward [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net, Total	$ (0.1)	$ (0.1)	$ 0.2	$ (0.1)

X

- Definition

The period of maturity for forward contracts.

+ References

No definition available.

+ Details

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X

- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CC
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL109998890-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959

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X

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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X

- Definition

Period remaining until the derivative contract matures, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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X

- Definition

Amount of unrealized loss recorded in accumulated other comprehensive income pertaining to the decrease in fair value of foreign currency exchange rate derivatives designated as cash flow hedging instruments to the extent that a cash flow hedge is determined to be effective.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959

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- Details

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- Details

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- Details

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