CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ 7,408	$ (5,952)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	8,403	12,356
Amortization of operating lease right-of-use assets	1,487	0
Amortization of debt issuance costs and discount	686	507
Gain on sale or maturity of marketable securities	(53)	(1)
(Gain) loss on forward contracts	(84)	99
Stock-based compensation expense	3,686	4,800
Impairment of operating lease right-of-use asset (recorded in Restructuring charges)	757	0
Loss (gain) on disposal of fixed assets	8	(58)
Changes in assets and liabilities:
Accounts receivable, net	5,284	(8,867)
Inventories	323	2,356
Prepaid expenses and other assets	(1,965)	(3,253)
Accounts payable and accrued expenses (includes restructuring)	330	1,567
Accrued payroll obligations	(2,788)	(1,441)
Operating lease liabilities, current and long-term portions	(2,089)	0
Income taxes payable	365	413
Deferred licensing and services revenue	0	(68)
Net cash provided by operating activities	21,758	2,458
Cash flows from investing activities:
Proceeds from sales of and maturities of short-term marketable securities	9,655	2,500
Purchases of marketable securities	0	(9,603)
Capital expenditures	(3,074)	(1,804)
Cash paid for software licenses	(1,739)	(1,837)
Net cash provided by (used in) investing activities	4,842	(10,744)
Cash flows from financing activities:
Restricted stock unit tax withholdings	(418)	(459)
Proceeds from issuance of common stock	11,986	1,608
Repayment of debt	(26,875)	(875)
Net cash (used in) provided by financing activities	(15,307)	274
Effect of exchange rate change on cash	47	589
Net increase (decrease) in cash and cash equivalents	11,340	(7,423)
Beginning cash and cash equivalents	119,051	106,815
Ending cash and cash equivalents	130,391	99,392
Supplemental cash flow information:
Interest paid	4,383	4,420
Operating lease payments	2,597	0
Income taxes paid, net of refunds	280	40
Accrued purchases of plant and equipment	1,417	232
Operating lease right-of-use assets obtained in exchange for lease obligations	219	0
Change in unrealized (gain) loss related to marketable securities, net of tax, included in Accumulated other comprehensive loss	$ (42)	$ 7