Operating Segments and Geographic Information (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Oct. 02, 2011	Jul. 03, 2011	Apr. 03, 2011	Dec. 31, 2010	Oct. 03, 2010	Jul. 04, 2010	Apr. 04, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Schedule of Revenue from External Customers and Long-Lived Assets based on physical location
Revenues	$ 464,361	$ 519,713	$ 536,251	$ 461,628	$ 425,176	$ 396,927	$ 410,563	$ 384,424	$ 1,981,953	$ 1,617,090	$ 1,362,016
Percent of total revenues									100.00%	100.00%	100.00%
Long-lived assets	350,765				341,688				350,765	341,688	360,213
United States [Member]
Schedule of Revenue from External Customers and Long-Lived Assets based on physical location
Revenues									908,229	703,836	587,580
Percent of total revenues									46.00%	43.00%	43.00%
Long-lived assets	142,925				133,864				142,925	133,864	131,098
Canada & Latin America [Member]
Schedule of Revenue from External Customers and Long-Lived Assets based on physical location
Revenues									277,375	208,694	166,907
Percent of total revenues									14.00%	13.00%	12.00%
Long-lived assets	20,398				17,858				20,398	17,858	20,121
Europe, Africa & Middle East [Member]
Schedule of Revenue from External Customers and Long-Lived Assets based on physical location
Revenues									413,195	371,933	342,045
Percent of total revenues									21.00%	23.00%	26.00%
Long-lived assets	126,642				125,762				126,642	125,762	140,430
Asia Pacific [Member]
Schedule of Revenue from External Customers and Long-Lived Assets based on physical location
Revenues									383,154	332,627	265,484
Percent of total revenues									19.00%	21.00%	19.00%
Long-lived assets	$ 60,800				$ 64,204				$ 60,800	$ 64,204	$ 68,564