Schedule Of Net Revenue By Geography Periods (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 31, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total net revenues	$ 353,182	$ 353,338	$ 337,604	$ 349,391	$ 356,620	$ 361,895	$ 357,719	$ 293,399	$ 1,393,515	$ 1,369,633	$ 1,271,921
United States [Member]
Segment Reporting Information [Line Items]
Total net revenues									750,933	769,357	660,998
Americas Excluding United States [Member]
Segment Reporting Information [Line Items]
Total net revenues									19,957	19,961	18,421
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total net revenues									154,503	142,729	184,404
EMEA Excluding United Kingdom [Member]
Segment Reporting Information [Line Items]
Total net revenues									267,384	269,959	273,320
APAC [Member]
Segment Reporting Information [Line Items]
Total net revenues									$ 200,738	$ 167,627	$ 134,778