Segment and Geographic Data, Revenue and assets by geographic area (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 610,764	$ 638,211	$ 641,929	$ 602,378	$ 616,170	$ 602,890	$ 597,665	$ 554,254	$ 2,493,282	$ 2,370,979	$ 2,230,097
Property and equipment, net	898,095				926,619				898,095	926,619
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									590,145	591,082	568,849
Property and equipment, net	116,807				123,812				116,807	123,812
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									821,005	800,733	775,204
Property and equipment, net	124,850				130,854				124,850	130,854
Czech Republic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	38,914				47,002				38,914	47,002
Other Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									107,598	89,348	61,236
Property and equipment, net	94,377				107,381				94,377	107,381
Israel [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									13,871	13,319	14,708
Property and equipment, net	121,691				138,741				121,691	138,741
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									960,663	876,497	810,100
People's Republic of China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	176,671				172,274				176,671	172,274
Republic of China (Taiwan) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	127,354				120,368				127,354	120,368
Other Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	95,263				84,388				95,263	84,388
Other Geographic Area [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 2,168				$ 1,799				$ 2,168	$ 1,799