Segment Information, Operations By Geographic Area And Customer Concentration (Schedule Of Net Revenue By Geography Periods) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jul. 01, 2012	Apr. 01, 2012	Dec. 31, 2011	Oct. 02, 2011	Jul. 03, 2011	Apr. 03, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Total net revenues	$ 310,436	$ 315,210	$ 320,655	$ 325,620	$ 309,155	$ 301,800	$ 291,240	$ 278,823	$ 1,271,921	$ 1,181,018	$ 902,052
United States [Member]
Segment Reporting Information [Line Items]
Total net revenues									660,998	570,143	454,179
Americas (excluding U.S.) [Member]
Segment Reporting Information [Line Items]
Total net revenues									18,421	16,913	12,363
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total net revenues									184,404	165,522	100,357
EMEA (excluding U.K.) [Member]
Segment Reporting Information [Line Items]
Total net revenues									273,320	312,191	239,892
APAC [Member]
Segment Reporting Information [Line Items]
Total net revenues									$ 134,778	$ 116,249	$ 95,261