Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual) - USD ($)		12 Months Ended
	Dec. 12, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019	Jan. 01, 2018	Aug. 04, 2016
Foreign Currency Transaction Gain (Loss), before Tax, Total		$ (135,000)	$ 22,000	$ (434,000)
Inventory Valuation Reserves, Ending Balance		6,188,000	3,133,000
Goodwill, Impairment Loss		0	0	0
Revenue from Contract with Customer, Excluding Assessed Tax, Total		294,490,000	348,201,000	266,277,000
Cost of Goods and Services Sold, Total		129,345,000	151,698,000	85,581,000
Inventory, Net, Total		33,052,000	31,721,000
Standard and Extended Product Warranty Accrual, Ending Balance		110,000	110,000
Reimbursements from Research and Development Contracts		$ 0	$ 3,000,000	$ 2,400,000
Effective Income Tax Rate Reconciliation, at Highest Federal Statutory Income Tax Rate, Percent			35.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	34.00%	34.00%
Deferred Tax Liabilities, Net, Current		$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate		0.00%
Number of Reportable Segments		1
Assets, Total		$ 889,873,000	$ 917,506,000
Liabilities, Total		$ 523,179,000	$ 506,105,000
Licenses for Intellectual Property [Member]
Percent of Revenue From Nonproduct Sales		3.00%	3.00%	1.00%
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life		1 year
Product Warranty Term		1 year
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life		10 years
Product Warranty Term		2 years
Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 0				$ 0
Accounting Standards Update 2014-09 [Member]
Revenue from Contract with Customer, Excluding Assessed Tax, Total		3,778,000
Cost of Goods and Services Sold, Total		779,000
Deferred Revenue		3,778,000
Inventory, Net, Total		779,000
Contract with Customer, Refund Liability, Total		$ 1,634,000
Accounting Standards Update 2016-02 [Member] | Minimum [Member] | Subsequent Event [Member]
Assets, Total					$ 10,000,000
Liabilities, Total					10,000,000
Accounting Standards Update 2016-02 [Member] | Maximum [Member] | Subsequent Event [Member]
Assets, Total					12,000,000
Liabilities, Total					$ 12,000,000
ClariPhy Communications Inc.[Member]
Payments to Acquire Businesses, Gross	$ 303,661,000
Memory Product Business [Member] | Discontinued Operations, Held-for-sale [Member] | Rambus Inc. [Member]
Disposal Group, Including Discontinued Operation, Consideration							$ 90,000,000