Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Cash flows from operating activities:
Net income	$ 8,167	$ 7,408
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,793	8,403
Stock-based compensation expense	8,728	3,686
Reduction in the carrying amount of right-of-use assets	1,494	1,487
Amortization of debt issuance costs and discount	103	686
Impairment of operating lease right-of-use asset (recorded in Restructuring charges)	0	757
Other non-cash adjustments	(88)	(129)
Changes in assets and liabilities:
Accounts receivable, net	(3,726)	5,284
Inventories	6,048	323
Prepaid expenses and other assets	(129)	(1,965)
Accounts payable and accrued expenses	130	330
Accrued payroll obligations	(5,689)	(2,788)
Operating lease liabilities, current and long-term portions	(1,437)	(2,089)
Income taxes payable	(291)	365
Net cash provided by operating activities	21,103	21,758
Cash flows from investing activities:
Proceeds from sales of and maturities of short-term marketable securities	0	9,655
Capital expenditures	(3,867)	(3,074)
Cash paid for software licenses	(2,775)	(1,739)
Net cash (used in) provided by investing activities	(6,642)	4,842
Cash flows from financing activities:
Restricted stock unit tax withholdings	(3,854)	(418)
Proceeds from issuance of common stock	2,370	11,986
Proceeds from issuance of long-term debt	50,000	0
Repayment of debt	(4,375)	(26,875)
Net cash provided by (used in) financing activities	44,141	(15,307)
Effect of exchange rate change on cash	(111)	47
Net increase in cash and cash equivalents	58,491	11,340
Beginning cash and cash equivalents	118,081	119,051
Ending cash and cash equivalents	176,572	130,391
Interest paid	1,113	4,383
Operating lease payments	1,934	2,597
Income taxes paid, net of refunds	852	280
Accrued purchases of plant and equipment	753	1,417
Operating lease right-of-use assets obtained in exchange for lease obligations	$ 49	$ 219