Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jul. 04, 2015		Jun. 28, 2014
Cash flows from operating activities:
Net loss	$ (148)		$ (10,861)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	3,244		3,076
Amortization of intangibles and other	1,223		1,327
Amortization of security premium	(64)		(54)
Stock-based compensation	8,200		8,067
Changes in operating assets and liabilities:
Accounts receivable	12,206		5,236
Inventories	(4,946)		(2,037)
Prepaid expenses and other current assets	729		320
Other assets	(129)		(240)
Accounts payable	(341)		3,387
Deferred product and services income	(1,712)		605
Other current liabilities	657		(3,930)
Other liabilities	(906)		(139)
Net cash provided by operating activities	18,013		4,757
Cash flows from investing activities:
Capital expenditures	(1,765)		(1,183)
Purchase of investments in securities	(110,454)		(119,607)
Proceeds from maturities of investments	102,617		110,778
Net cash used in investing activities	(9,602)		(10,012)
Cash flows from financing activities:
Proceeds from notes payable	10,240		10,240
Repayment of notes payable	(10,240)		(10,240)
Proceeds from issuance of common stock for stock option exercises	218		2,252
Tax payment for issuance of common stock from release of restricted stock units	(1,750)		(2,736)
Payments for Repurchase of Common Stock	(5,078)		0
Net cash used in financing activities	(6,610)		(484)
Net increase (decrease) in cash and cash equivalents	1,801		(5,739)
Cash and cash equivalents at beginning of period	67,988	[1]	93,550
Cash and cash equivalents at end of period	69,789		87,811
Other non-cash changes:
Systems transferred from (to) inventory to (from) equipment and other assets, net	$ (1,325)		$ 258

[1] The balance sheet as of December 31, 2014 has been derived from the audited financial statements at that date.