CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (71,110)	$ (61,871)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of intangibles	6,232	12,711
Depreciation	11,045	13,198
Stock-based compensation	11,107	8,542
Amortization of discount on convertible debt and issuance cost	4,060	3,669
Restructuring, asset impairment and loss on retirement of fixed assets	565	1,476
Amortization of non-cash warrant	38	0
Loss on impairment of long-term investment	0	2,735
Foreign currency adjustments	1,795	(911)
Provision for excess and obsolete inventories	5,578	6,246
Allowance for doubtful accounts and returns	4,309	1,222
Other non-cash adjustments, net	298	251
Changes in operating assets and liabilities, net of effects of acquisition:
Accounts receivable	11,367	(12,869)
Inventories	6,188	2,225
Prepaid expenses and other assets	6,702	(5,938)
Accounts payable	2,129	2,505
Deferred revenue	(1,098)	20,038
Income taxes payable	(2,122)	(827)
Accrued and other liabilities	(3,053)	(5,040)
Net cash used in operating activities	(5,970)	(12,638)
Cash flows from investing activities:
Acquisition of business, net of cash acquired	0	(75,669)
Proceeds from maturities of investments	3,106	18,692
Proceeds from sales of investments	3,792	0
Purchases of property and equipment	(9,075)	(11,423)
Net cash used in investing activities	(2,177)	(68,400)
Cash flows from financing activities:
Payment of convertible debt issuance costs	0	(582)
Proceeds from other debts and capital leases	6,344	5,968
Repayment of other debts and capital leases	(7,008)	(8,038)
Proceeds from common stock issued to employees	4,697	3,736
Payment of tax withholding obligations related to net share settlements of restricted stock units	(2,757)	(1,313)
Net cash provided by (used in) financing activities	1,276	(229)
Effect of exchange rate changes on cash and cash equivalents	1,275	(182)
Net decrease in cash and cash equivalents	(5,596)	(81,449)
Cash and cash equivalents at beginning of period	55,635	126,190
Cash and cash equivalents at end of period	$ 50,039	$ 44,741