Note 16 - Segment and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2014

Segment Reporting [Abstract]

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

	Year Ended December 31,
Country or Region	2014		2013		2012
China	$	181,050	$	141,400	$	124,278
Taiwan		38,460		34,248		27,477
Europe		19,830		15,351		16,201
Korea		14,362		9,992		9,434
Southeast Asia		13,993		21,760		21,641
Japan		8,251		7,495		8,516
United States		6,392		7,525		5,711
Other		197		320		555
Total	$	282,535	$	238,091	$	213,813

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

	Year Ended December 31,
Product Family	2014		2013		2012
DC to DC products	$	253,083	$	211,337	$	188,736
Lighting control products		29,452		26,754		25,077
Total	$	282,535	$	238,091	$	213,813

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

	As of December 31,
Country	2014		2013
China	$	37,147	$	41,557
United States		33,913		24,719
Bermuda		13,383		-
Other		339		205
Total	$	84,782	$	66,481