Restructuring and Related Activities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014 MOSFETs Enhanced Competitiveness Program [Member]	Dec. 31, 2013 MOSFETs Enhanced Competitiveness Program [Member]	Jun. 28, 2014 MOSFETs Enhanced Competitiveness Program [Member]	Jun. 28, 2014 Voluntary Separation/Retirement Program [Member]	Dec. 31, 2013 Voluntary Separation/Retirement Program [Member]	Jun. 28, 2014 Voluntary Separation/Retirement Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Current					$ 1,243		$ 1,243	$ 7,598		$ 7,598
Restructuring and related expense	9,014		15,418		1,492		3,219	7,522		12,199
Restructuring Reserve [Roll Forward]
Restructuring and severance costs	9,014	0	15,418	0		2,328	3,219		486	12,199
Cash paid						(267)	(113)		(98)	(4,974)
Foreign currency translation									3	(18)
Balance at end of period					5,167	2,061	5,167	7,598	391	7,598
Balance at beginning of period							2,061			391
Term of restructuring program					2 years
Expected Restructuring Costs			$ 31,700				$ 16,000