Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011	Jan. 02, 2010
Cash flows from operating activities:
Net income (loss)	$ 28,685	$ 55,948	$ (16,305)
Reconciliation of net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	6,488	5,858	6,092
Asset impairment	0	463	1,899
Stock-based compensation	4,473	2,950	2,054
Excess tax benefit from equity awards	(3,915)	(801)	0
(Gain) Loss on disposal of asset	113	(140)	82
Inventory write down	1,916	1,457	376
Deferred taxes	3,770	(17,233)	(426)
Unrealized foreign exchange loss (gain)	0	(523)	939
Changes in fair value of contingent payments to Zygo	413	467	596
Changes in assets and liabilities, net of effects of assets acquired and liabilities assumed in acquisitions:
Accounts receivable	16,172	(20,996)	(5,971)
Inventories	(12,169)	(14,495)	1,572
Inventories-delivered systems	446	244	(975)
Prepaid expenses and other	(4,747)	(398)	(113)
Accounts payable, accrued and other liabilities	4,241	11,533	775
Deferred revenue	3,088	1,414	3,941
Income taxes payable	5,054	1,879	(291)
Net cash provided by (used in) operating activities	54,028	27,627	(5,755)
Cash flows from investing activities:
Cash received from Tevet on escrow settlement	0	0	215
Payments to Zygo, related to acquisition	(432)	(3,503)	0
Purchase of Nanda's net assets, net of cash received	(23,912)	0	0
Purchases of property, plant and equipment	(2,755)	(3,096)	(822)
Proceeds from sale of property, plant and equipment	0	492	9
Net cash used in investing activities	(27,099)	(6,107)	(598)
Cash flows from financing activities:
Borrowings from line of credit	0	0	7,000
Repayment of line of credit	0	0	(7,000)
Repayments of debt obligations	(2,571)	(2,999)	(319)
Proceeds from sale of stock under employee stock purchase and stock option plans	7,186	5,784	3,038
Proceeds from issuance of common stock offering, net of $0, $0 and $426 offering cost for 2011, 2010 and 2009 respectively	0	(28)	23,292
Excess tax benefit from equity awards	3,915	801	0
Taxes on net issuance of stock awards	(126)	(299)	0
Repurchases of common stock	(4,257)	(2,097)	0
Net cash provided by financing activities	4,147	1,162	26,011
Effect of exchange rate changes on cash and cash equivalents	163	252	(112)
Net increase in cash and cash equivalents	31,239	22,934	19,546
Cash and cash equivalents, beginning of period	66,460	43,526	23,980
Cash and cash equivalents, end of period	97,699	66,460	43,526
Supplemental disclosure of cash flow information:
Cash paid for interest	757	965	1,038
Cash paid for income taxes	$ 11,149	$ 1,572	$ 153