CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 26, 2020	Jun. 28, 2019
Cash flows from operating activities:
Net loss	$ (37,355)	$ (23,151)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of intangibles	2,462	4,162
Depreciation	5,535	5,716
Stock-based compensation	9,807	4,623
Amortization of discount on convertible and other debt	3,785	3,262
Amortization of non-cash warrant	868	48
Loss on debt extinguishment	834	0
Deferred income taxes, net	1,116	(145)
Provision for excess and obsolete inventories	723	384
Provision for doubtful accounts, returns and discounts	662	500
Other non-cash adjustments, net	118	79
Changes in operating assets and liabilities:
Accounts receivable	13,024	10,699
Inventories	(4,032)	(2,440)
Prepaid expenses and other assets	19,182	(1,526)
Accounts payable	(14,963)	(1,752)
Deferred revenue	11,241	4,989
Income taxes payable	(181)	(292)
Accrued and other liabilities	(11,936)	(9,802)
Net cash provided by (used in) operating activities	890	(4,646)
Cash flows from investing activities:
Purchases of property and equipment	(20,753)	(2,939)
Net cash used in investing activities	(20,753)	(2,939)
Cash flows from financing activities:
Payments of convertible debt	(25)
Payment of convertible debt issuance costs	(35)	0
Proceeds from other debts and finance leases	9,398	4,503
Repayment of other debts and finance leases	(6,342)	(6,162)
Proceeds from common stock issued to employees	3,000	2,147
Payment of tax withholding obligations related to net share settlements of restricted stock units	(1,049)	(828)
Net cash provided by (used in) financing activities	4,947	(340)
Effect of exchange rate changes on cash and cash equivalents	(398)	0
Net decrease in cash and cash equivalents	(15,314)	(7,925)
Cash, cash equivalents and restricted cash at beginning of period	93,058	65,989
Cash, cash equivalents and restricted cash at end of period	77,744	58,064
Supplemental disclosures of cash flow information:
Income tax payments, net	809	860
Interest payments, net	2,037	2,495
Supplemental schedule of non-cash investing and financing activities:
Capital expenditures incurred but not yet paid	5,000	$ 78
Fair value of Convertible Senior Notes due 2022 used to settle Convertible Senior Notes due 2020	$ 44,357