Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 03, 2020	Sep. 28, 2019
Cash Flows from Operating Activities
Net loss	$ (138,255)	$ (199,876)
Adjustments to reconcile net loss to net cash used in operating activities:
Provision for doubtful accounts	461	29
Provision for excess and obsolete inventory	14,189	5,163
Depreciation	33,332	43,215
Non-cash lease expense	11,082	17,961
Accelerated depreciation of property and equipment	726	169
Amortization of intangible assets	8,351	6,100
Stock-based compensation	57,877	59,175
Deferred income taxes	(11,289)	618
Other	585	(50)
Changes in operating assets and liabilities, net of acquisition:
Accounts receivable	76,356	68,617
Inventories	21,410	(125,500)
Prepaid expenses and other assets	(9,136)	5,880
Income taxes receivable	(39,679)	5,992
Accounts payable	(23,028)	11,826
Accrued liabilities and other liabilities	(66,763)	(60,763)
Lease liabilities	(14,432)	(20,975)
Deferred revenue	13,802	(2,586)
Income taxes payable	1,803	(107)
Net cash used in operating activities	(62,608)	(185,112)
Cash Flows from Investing Activities
Purchase of property and equipment	(22,419)	(26,277)
Purchases of marketable securities	(59,735)	(287,969)
Sales of marketable securities	0	2,016
Maturities of marketable securities	200,877	322,132
Acquisition, net of cash acquired	0	(2,625)
Net cash provided by investing activities	118,723	7,277
Cash Flows from Financing Activities
Payment of financing lease liability	(1,384)	(2,239)
Proceeds from issuance of common stock	2,990	7,044
Taxes paid related to net share settlement of restricted stock units	(18,816)	(13,495)
Net cash used in financing activities	(17,210)	(8,690)
Net increase (decrease) in cash and cash equivalents	38,905	(186,525)
Cash and cash equivalents at beginning of period	334,479	473,956
Cash and cash equivalents at end of period	$ 373,384	$ 287,431