CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016
Operating activities
Net income (loss)	$ 1,829	$ (6,305)
Adjustments to reconcile net income (loss) to net cash and cash equivalents used in operating activities:
Depreciation and amortization	1,015	1,176
Net amortization of investment premiums and discounts	28	36
Equity-based compensation	1,077	1,111
Change in the fair value of acquisition-related contingent consideration	80	16
Changes in operating assets and liabilities	(6,010)	1,518
Total adjustments	(3,810)	3,857
Net cash and cash equivalents used in operating activities	(1,981)	(2,448)
Investing activities
Purchases of investments	(3,944)	(2,109)
Proceeds from sales and maturities of investments	5,850	13,305
Decrease in restricted cash	152
Purchases of leasehold improvements and equipment	(1,448)	(1,250)
Net cash and cash equivalents provided by investing activities	610	9,946
Financing activities
Proceeds from issuance of common stock	1,083	711
Taxes paid related to net share settlement	(1,210)	(222)
Payment of acquisition-related contingent consideration	(2)
Net cash and cash equivalents provided by (used in) financing activities	(129)	489
Effect of exchange rate changes on cash and cash equivalents	34	67
Net increase (decrease) in cash and cash equivalents	(1,466)	8,054
Cash and cash equivalents at beginning of period	27,043	13,746
Cash and cash equivalents at end of period	$ 25,577	$ 21,800