Segment and Geographic Data, Revenue and assets by geographic area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 31, 2015	Oct. 03, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 570,819	$ 591,955	$ 590,051	$ 570,606	$ 555,928	$ 560,654	$ 590,470	$ 593,436	$ 2,323,431	$ 2,300,488	$ 2,493,282
Property and equipment, net	848,871				865,296				848,871	865,296
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									542,506	560,973	590,145
Property and equipment, net	94,589				94,512				94,589	94,512
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									746,657	719,246	821,005
Property and equipment, net	120,223				122,817				120,223	122,817
Czech Republic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	29,912				33,352				29,912	33,352
Other Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									83,744	88,553	107,598
Property and equipment, net	83,041				85,566				83,041	85,566
Israel [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									10,007	12,597	13,871
Property and equipment, net	104,824				107,715				104,824	107,715
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									940,517	919,119	$ 960,663
People's Republic of China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	183,158				182,411				183,158	182,411
Republic of China (Taiwan) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	124,724				126,780				124,724	126,780
Other Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	105,400				109,815				105,400	109,815
Other Geographic Area [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 3,000				$ 2,328				$ 3,000	$ 2,328