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
	Mar. 31, 2013	Apr. 01, 2012
Segment Reporting Information [Line Items]
Total net revenues	$ 293,399	$ 325,620
United States [Member]
Segment Reporting Information [Line Items]
Total net revenues	153,713	164,745
Americas (excluding U.S.) [Member]
Segment Reporting Information [Line Items]
Total net revenues	2,963	3,610
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total net revenues	40,858	49,394
EMEA (excluding U.K.) [Member]
Segment Reporting Information [Line Items]
Total net revenues	66,267	75,687
APAC [Member]
Segment Reporting Information [Line Items]
Total net revenues	$ 29,598	$ 32,184