Quarterly Financial Data (Details) (USD $) In Thousands, except Per Share data, 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
Quarterly Financial Data [Abstract]
Net revenue	$ 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
Gross Profit	100,474		102,333	97,186	97,925	100,789	101,659	103,430	87,737	397,918	393,615	383,553
Provision for income taxes	(5,609)		8,847	9,698	9,037	11,712	10,364	7,144	8,545	21,973	37,765	42,743
Net Income	$ (40,353)	[1]	$ 20,025	$ 14,705	$ 14,411	$ 11,432	$ 14,457	$ 13,985	$ 15,343	$ 8,788	$ 55,217	$ 86,539
Basic net income per share (in dollars per share)	$ (1.16)		$ 0.56	$ 0.41	$ 0.39	$ 0.30	$ 0.37	$ 0.36	$ 0.40	$ 0.25	$ 1.44	$ 2.27
Diluted net income per share (in dollars per share)	$ (1.16)		$ 0.55	$ 0.40	$ 0.39	$ 0.30	$ 0.37	$ 0.36	$ 0.39	$ 0.24	$ 1.42	$ 2.23

[1] Net loss includes a non-cash goodwill impairment charge of $74.2 million relating to the service provider business unit.