Schedule Of Reportable Segment And Reconciliation Of Segment Contribution Income To Income Before Income Taxes (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
Total segment contribution income									194,623	191,544	195,428
Corporate and unallocated costs									(53,581)	(51,629)	(47,766)
Amortization of intangible assets									(17,573)	(15,217)	(4,763)	[1]
Stock-based compensation expense									(20,014)	(17,462)	(14,372)
Restructuring and other charges									(2,209)	(5,335)	(1,190)
Acquisition-related expense									(8)	(940)	(833)	[2]
Impact to cost of sales from acquisition accounting adjustments to inventory									0	(568)	0
Litigation reserves, net									1,011	(5,354)	(390)
Goodwill impairment charges									(74,196)	0	0
Intangibles Impairment charges									0	(2,000)	0
Interest income									253	400	498
Other income (expense), net									2,455	(457)	2,670
Income before income taxes									30,761	92,982	129,282
Retail [Member]
Segment Reporting Information [Line Items]
Total net revenues									508,100	509,924	504,797
Total segment contribution income									76,266	73,418	86,808
Segment contribution margin (in percentage)									15.00%	14.40%	17.20%
Goodwill impairment charges									0	0	0
Commercial [Member]
Segment Reporting Information [Line Items]
Total net revenues									305,677	311,261	307,945
Total segment contribution income									70,810	66,506	67,826
Segment contribution margin (in percentage)									23.20%	21.40%	22.00%
Goodwill impairment charges									0	0	0
Service Provider [Member]
Segment Reporting Information [Line Items]
Total net revenues									579,738	548,448	459,179
Total segment contribution income									47,547	51,620	40,794
Segment contribution margin (in percentage)									8.20%	9.40%	8.90%
Goodwill impairment charges									$ (74,196)	$ 0	$ 0

[1] Amount excludes amortization expense related to patents within purchased intangibles in costs of revenues.

[2] These acquisition-related charges were expensed in the period incurred and reported in the Company's consolidated statements of operations within cost of revenues and operating expense.