Note 12 - Income Tax (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Tax Credit Carryforward Duration Limit	20 years
Undistributed Earnings of Foreign Subsidiaries	$ 297,631	$ 267,899
Unrecognized Tax Benefits	148	292	$ 494
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	148	292
Tax Adjustments, Settlements, and Unusual Provisions	12	34
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 38	$ 50
Minimum [Member] \| Foreign Tax Authority [Member] \| Canada Revenue Agency [Member]
Income Tax Return Examination Period	3 years
Minimum [Member] \| Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member]
Income Tax Return Examination Period	3 years
Maximum [Member] \| Foreign Tax Authority [Member] \| Canada Revenue Agency [Member]
Income Tax Return Examination Period	4 years
Maximum [Member] \| Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member]
Income Tax Return Examination Period	5 years
Canada and United States [Member] \| Minimum [Member]
Tax Credit Carryforward Duration Limit	6 years
Canada and United States [Member] \| Maximum [Member]
Tax Credit Carryforward Duration Limit	20 years

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile.

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Amount of unrecognized tax benefits.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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