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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019	Jan. 01, 2018
Foreign Currency Transaction Gain (Loss), before Tax, Total	$ 953	$ (550)	$ 65
Available-for-sale Securities, Total	248,953	229,221
Goodwill, Impairment Loss	0	0	0
Cumulative Effect of New Accounting Principle in Period of Adoption	379
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 379	(5,141)
Accounting Standards Update 2014-09 [Member] \| Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 400
Minimum [Member]
Warranty Term	1 year
Minimum [Member] \| Accounting Standards Update 2016-02 [Member] \| Subsequent Event [Member]
Operating Lease, Right-of-Use Asset				$ 2,000
Operating Lease, Liability, Total				2,000
Minimum [Member] \| Know-How And Developed Technologies [Member]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum [Member]
Warranty Term	2 years
Maximum [Member] \| Accounting Standards Update 2016-02 [Member] \| Subsequent Event [Member]
Operating Lease, Right-of-Use Asset				3,000
Operating Lease, Liability, Total				$ 3,000
Maximum [Member] \| Know-How And Developed Technologies [Member]
Finite-Lived Intangible Asset, Useful Life	5 years
Building and Building Improvements [Member] \| Minimum [Member]
Property, Plant and Equipment, Useful Life	20 years
Building and Building Improvements [Member] \| Maximum [Member]
Property, Plant and Equipment, Useful Life	40 years
Computer Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Computer Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment, Useful Life	8 years
Transportation Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment, Useful Life	5 years
Transportation Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment, Useful Life	20 years
Furniture and Fixtures [Member] \| Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Furniture and Fixtures [Member] \| Maximum [Member]
Property, Plant and Equipment, Useful Life	5 years
Auction Rate Securities [Member]
Available-for-sale Securities, Total	$ 3,200	5,300
Interest and Other Income [Member]
Foreign Currency Transaction Gain (Loss), before Tax, Total	$ 1,000	$ (600)	$ 100