Note 1 - Organization and Summary of Significant Accounting Policies - Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	[1]	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	[2]	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 102,896	$ 94,231	$ 86,285	$ 82,223	$ 86,531		$ 78,009	$ 69,814	$ 60,136		$ 365,635	$ 294,490	$ 348,201
CHINA
Revenue											164,715	113,684	114,168
UNITED STATES
Revenue											103,402	87,545	92,620
THAILAND
Revenue											54,468	40,884	45,205
Other Country [Member]
Revenue											$ 43,050	$ 52,377	$ 96,208

[1] The Company recorded a charge of $7,000 due to impairment of a non-marketable equity investment.

[2] The benefit for income taxes included partial release of federal valuation allowance resulting from the transfer of an acquired in-process research and development to developed technology in 2018 which allowed the related deferred tax liability to be considered a source of income for realizing deferred tax assets, as well as the revaluation of the foreign deferred tax liability on the in-process research and development based on the foreign tax rates applicable to the anticipated reversal periods.