Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012
Cash flows from operating activities:
Net income (loss)	$ (14,702)	$ 8,112
Reconciliation of net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	6,536	5,991
Stock-based compensation	5,912	4,535
Excess tax benefit from equity awards	467	(939)
Loss on disposal of fixed assets	173	246
Inventory write down	6,307	2,602
Deferred income taxes	(9,659)	2,948
Changes in fair value of contingent consideration	1,045	307
Changes in assets and liabilities:
Accounts receivable	(1,818)	(831)
Inventories	(7,173)	(429)
Inventories-delivered systems	(300)	(571)
Prepaid expenses and other	820	(1,655)
Accounts payable, accrued and other liabilities	6,798	(12,242)
Deferred revenue	2,044	4,418
Income taxes payable	(363)	283
Net cash provided by (used in) operating activities	(3,913)	12,775
Cash flows from investing activities:
Maturities of marketable securities	38,030	500
Escrow payment received related to Nanda acquisition	0	508
Sales of marketable securities	0	3,000
Purchases of marketable securities	(40,797)	(40,929)
Purchases of property, plant and equipment	(3,516)	(3,705)
Net cash used in investing activities	(6,283)	(40,626)
Cash flows from financing activities:
Payments of contingent consideration	(735)	(232)
Repayments of debt obligations	(5,224)	(1,989)
Proceeds from sale of shares under employee stock option plans and purchase plans	3,192	3,463
Excess tax benefit from equity awards	(467)	939
Taxes paid on net issuance of stock awards	(86)	(16)
Repurchases of common stock	(5,000)	(4,960)
Net cash used in financing activities	(8,320)	(2,795)
Effect of exchange rate changes on cash and cash equivalents	(566)	411
Net decrease in cash and cash equivalents	(19,082)	(30,235)
Cash and cash equivalents, beginning of period	62,915	97,699
Cash and cash equivalents, end of period	$ 43,833	$ 67,464