Restructuring and Related Activities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013	Mar. 29, 2014 MOSFETs Enhanced Competitiveness Program [Member]	Dec. 31, 2013 MOSFETs Enhanced Competitiveness Program [Member]	Mar. 29, 2014 Voluntary Separation/Retirement Program [Member]	Dec. 31, 2013 Voluntary Separation/Retirement Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Current			$ 908		$ 3,274
Restructuring and related expense	6,404		1,727		4,677
Restructuring Reserve [Roll Forward]
Restructuring and severance costs	6,404	0	1,727	2,328	4,677	486
Cash paid			(113)	(267)	(1,791)	(98)
Foreign currency translation					(3)	3
Balance at end of period			3,675	2,061	3,274	391
Balance at beginning of period			2,061		391
Term of restructuring program			2 years
Expected Restructuring Costs	$ 32,000		$ 16,000