CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Operating activities
Net loss	$ (7,441)	$ (9,166)	$ (27,445)
Adjustments to reconcile net loss to net cash and cash equivalents provided by (used in) operating activities:
Depreciation & amortization	3,983	3,743	3,769
Net amortization (accretion) of investment premiums and discounts	128	319	655
Amortization of intangible assets	854	854	936
Equity-based compensation	3,744	3,620	3,000
Deferred income taxes	9	(12)	(728)
Deferred income taxes valuation allowance			9,394
Change in the fair value of acquisition-related contingent consideration	(100)	(244)	(250)
Loss (gain) on disposal of equipment	(136)	271	41
Changes in assets and liabilities:
Accounts receivable	(5,137)	(223)	2,950
Inventories	(6,116)	452	3,550
Prepaid expenses and other assets	496	(1,382)	(166)
Accounts payable	(627)	1,310	629
Accrued payroll and other accrued liabilities	12,329	19	2,163
Customer advances	1,797	1,074	(1,192)
Total adjustments	11,224	9,801	24,751
Net cash and cash equivalents provided by (used in) operating activities	3,783	635	(2,694)
Investing activities
Purchase of investments	(12,429)	(21,058)	(35,703)
Proceeds from sales and maturities of investments	24,005	32,900	51,225
Proceeds from sale of equipment	208	11	13
Decrease (increase) in restricted cash	178		(1,780)
Purchase of equipment	(3,373)	(3,117)	(3,705)
Net cash and cash equivalents provided by investing activities	8,589	8,736	10,050
Financing activities
Proceeds from issuance of common stock	1,489	1,699	2,559
Common stock repurchases		(18,503)	(8,392)
Taxes paid related to net share settlement	(426)	(132)	(92)
Payment of acquisition-related contingent consideration	(31)
Net cash and cash equivalents used in financing activities	1,032	(16,936)	(5,925)
Effect of exchange rate changes on cash	(107)	(171)	(70)
Net increase (decrease) in cash and cash equivalents	13,297	(7,736)	1,361
Cash and cash equivalents at beginning of period	13,746	21,482	20,121
Cash and cash equivalents at end of period	27,043	13,746	21,482
Cash paid (received) for:
Income taxes	516	$ 1,190	$ 378
Income tax refund	$ (524)