Financial Information by Quarter (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Revenue:
Revenue	$ 384,567	$ 325,341	$ 296,250	$ 292,707	$ 332,058	$ 200,413	$ 208,227	$ 202,681	$ 1,298,865	$ 943,379	$ 740,739
Cost of revenue:
Amortization of intangible assets	8,437	7,796	8,098	8,252	8,315	4,876	4,943	5,341	32,583	23,475	20,474
Acquisition and integration costs	7,238	8,447	10,700	2,064	0	0	0	0	28,449	0	0
Restructuring and related	5,407	1,198	1,864	21,466	2,580	7	26	17	29,935	2,630	19,141
Total cost of revenue	273,161	238,512	234,994	226,275	247,554	130,234	123,922	120,513	972,942	622,223	496,739
Gross profit	111,406	86,829	61,256	66,432	84,504	70,179	84,305	82,168	325,923	321,156	244,000
Amortization of intangible assets	6,617	6,861	6,745	7,057	24,735	1,467	1,487	1,607	27,280	29,296	6,160
Acquisition and integration costs	11,011	11,962	12,164	7,134	13,463	2,067	0	0	42,271	15,530	322
Restructuring and related	18,024	2,168	3,471	17,188	10,804	191	1,680	(163)	40,851	12,512	16,106
Other operating expenses	136,625	135,125	147,260	146,741	149,726	91,612	102,757	105,402
Total operating expenses	172,277	156,116	169,640	178,120	198,728	95,337	105,924	106,846	676,153	506,835	427,087
Loss from operations	(60,871)	(69,287)	(108,384)	(111,688)	(114,224)	(25,158)	(21,619)	(24,678)	(350,230)	(185,679)	(183,087)
Other income (expense), net	(5,886)	(13,932)	(3,887)	(9,720)	(19,231)	(7,317)	(443)	(2,280)	(33,425)	(29,271)	(12,849)
Loss before income taxes	(66,757)	(83,219)	(112,271)	(121,408)	(133,455)	(32,475)	(22,062)	(26,958)	(383,655)	(214,950)	(195,936)
Provision for (benefit from) for income taxes	(163)	1,548	1,385	193	12	135	(124)	(678)	2,963	(655)	(1,430)
Net loss	$ (66,594)	$ (84,767)	$ (113,656)	$ (121,601)	$ (133,467)	$ (32,610)	$ (21,938)	$ (26,280)	$ (386,618)	$ (214,295)	$ (194,506)
Net loss per common share
Basic (in usd per share)	$ (0.37)	$ (0.47)	$ (0.64)	$ (0.69)	$ (0.76)	$ (0.21)	$ (0.14)	$ (0.17)	$ (2.16)	$ (1.36)	$ (1.32)
Diluted (in usd per share)	$ (0.37)	$ (0.47)	$ (0.64)	$ (0.69)	$ (0.76)	$ (0.21)	$ (0.14)	$ (0.17)	$ (2.16)	$ (1.36)	$ (1.32)
Product
Revenue:
Revenue	$ 307,861	$ 253,754	$ 226,866	$ 223,007	$ 249,608	$ 167,030	$ 175,288	$ 171,629	$ 1,011,488	$ 763,555	$ 610,535
Cost of revenue:
Cost of revenue	213,536	186,205	177,501	157,817	197,251	112,276	105,914	102,324	735,059	517,765	406,644
Services
Revenue:
Revenue	76,706	71,587	69,384	69,700	82,450	33,383	32,939	31,052	287,377	179,824	130,204
Cost of revenue:
Cost of revenue	$ 38,543	$ 34,866	$ 36,831	$ 36,676	$ 39,408	$ 13,075	$ 13,039	$ 12,831	$ 146,916	$ 78,353	$ 50,480