Note 17 - Segment and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area [Table Text Block]

	Year Ended December 31,
Country or Region	2018		2017		2016
China	$	334,726	$	257,787	$	245,169
Taiwan		75,307		83,357		45,414
Europe		49,484		38,140		27,554
Korea		41,238		34,155		27,710
Southeast Asia		36,495		25,755		19,645
Japan		26,853		20,187		14,318
United States		17,621		11,113		8,567
Other		658		435		288
Total	$	582,382	$	470,929	$	388,665

Revenue from External Customers by Products and Services [Table Text Block]

	Year Ended December 31,
Product Family	2018		2017		2016
DC to DC	$	537,512	$	431,861	$	350,930
Lighting Control		44,870		39,068		37,735
Total	$	582,382	$	470,929	$	388,665

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]

	December 31,
Country	2018		2017		2016
China	$	93,096	$	89,472	$	45,728
United States		71,025		65,618		50,242
Taiwan		16,972		17,238		8,919
Bermuda		6,682		7,522		9,573
Other		878		388		571
Total	$	188,653	$	180,238	$	115,033