Schedule Of Net Revenue By Geography Periods (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total net revenue	$ 397,057	$ 355,483	$ 330,723	$ 323,657	$ 367,929	$ 338,458	$ 311,655	$ 310,256	$ 1,406,920	$ 1,328,298	$ 1,300,695
United States [Member]
Segment Reporting Information [Line Items]
Total net revenue									927,952	855,796	779,361
Americas Excluding United States [Member]
Segment Reporting Information [Line Items]
Total net revenue									30,112	27,852	18,385
EMEA [Member]
Segment Reporting Information [Line Items]
Total net revenue									253,885	245,405	321,714
APAC [Member]
Segment Reporting Information [Line Items]
Total net revenue									$ 194,971	$ 199,245	$ 181,235