Financial Information by Quarter (Unaudited) - Unaudited Quarterly Consolidated Statements of Operations Data for Each of Eight Quarters (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 27, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Revenue:
Product	$ 158,492	$ 147,178	$ 142,364	$ 124,242	$ 115,102	$ 121,332	$ 120,647	$ 108,343	$ 572,276	$ 465,424	$ 380,035
Services	27,814	26,381	23,035	18,573	23,990	20,688	17,738	16,282	95,803	78,698	58,402
Total revenue	186,306	173,559	165,399	142,815	139,092	142,020	138,385	124,625	668,079	544,122	438,437
Cost of revenue:
Cost of product	89,809	86,703	85,906	78,438	73,385	66,685	80,198	75,447	340,856	295,715	259,437
Cost of services	12,154	11,554	9,240	5,971	9,795	6,964	6,533	6,476	38,919	29,768	21,431
Total cost of revenue	101,963	98,257	95,146	84,409	83,180	73,649	86,731	81,923	379,775	325,483	280,868
Gross profit	84,343	75,302	70,253	58,406	55,912	68,371	51,654	42,702	288,304	218,639	157,569
Operating expenses	71,477	67,822	62,201	59,462	62,993	61,926	60,262	57,644	260,962	242,825	240,570
Income (loss) from operations	12,866	7,480	8,052	(1,056)	(7,081)	6,445	(8,608)	(14,942)	27,342	(24,186)	(83,001)
Other income (expense), net	(2,773)	(2,432)	(2,655)	(3,070)	(2,683)	(2,790)	(800)	(6)	(10,930)	(6,279)	(139)
Income (loss) before income taxes	10,093	5,048	5,397	(4,126)	(9,764)	3,655	(9,408)	(14,948)	16,412	(30,465)	(83,140)
Provision for income taxes	1,683	205	617	248	414	308	601	331	2,753	1,654	2,190
Net income (loss)	$ 8,410	$ 4,843	$ 4,780	$ (4,374)	$ (10,178)	$ 3,347	$ (10,009)	$ (15,279)	$ 13,659	$ (32,119)	$ (85,330)
Net income (loss) per common share
Basic (in usd per share)	$ 0.07	$ 0.04	$ 0.04	$ (0.04)	$ (0.08)	$ 0.03	$ (0.09)	$ (0.13)	$ 0.11	$ (0.27)	$ (0.77)
Diluted (in usd per share)	$ 0.06	$ 0.04	$ 0.04	$ (0.04)	$ (0.08)	$ 0.03	$ (0.09)	$ (0.13)	$ 0.11	$ (0.27)	$ (0.77)