Note 13 - Segment Information (Detail) - Revenue By Product Family (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue (in Dollars)	$ 213,813	$ 196,519	$ 218,840
Percent of Revenue	100.00%	100.00%	100.00%
Percent Change	8.80%	(10.20%)
DC To DC Converters [Member]
Revenue (in Dollars)	188,736	170,032	190,286
Percent of Revenue	88.30%	86.50%	87.00%
Percent Change	11.00%	(10.60%)
Lighting Control Products [Member]
Revenue (in Dollars)	$ 25,077	$ 26,487	$ 28,554
Percent of Revenue	11.70%	13.50%	13.00%
Percent Change	(5.30%)	(7.20%)