SIGNIFICANT CUSTOMERS AND EXPORT SALES (Product Sales) (Details) (Sales Revenue, Goods, Net [Member])	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Product Concentration Risk [Member] | LinkSwitch [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	41.00%	40.00%
Product Concentration Risk [Member] | TinySwitch [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	33.00%	35.00%
Product Concentration Risk [Member] | TOPSwitch [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	23.00%	23.00%
Product Concentration Risk [Member] | Other Product Families [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	3.00%	2.00%
Minimum [Member] | Other Product Families [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	1.00%
Minimum [Member] | Product Concentration Risk [Member] | Primary Low Power AC DC Power Conversion Products [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	97.00%	97.00%
Minimum [Member] | Product Concentration Risk [Member] | Other Product Families [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues		1.00%
Maximum [Member] | Other Product Families [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	3.00%
Maximum [Member] | Product Concentration Risk [Member] | Primary Low Power AC DC Power Conversion Products [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues	99.00%	99.00%
Maximum [Member] | Product Concentration Risk [Member] | Other Product Families [Member]
Revenue from External Customer [Line Items]
Concentration risk, percentage of total net revenues		3.00%