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	$ 40,191	$ 25,514	$ 3,330
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,312	7,541	8,074
Loss on disposal of property and equipment	599	204	202
Stock based compensation	8,784	8,165	7,562
Deferred income taxes, net	6,154	(4,998)	(1,078)
Tax benefit of excess stock based compensation deductions	(6,917)	(2,622)	(2,239)
Non-cash director deferred compensation	162	132	132
Changes in operating assets and liabilities - (use) source
Accounts receivable	(9,282)	1,115	759
Unbilled revenue	1,650	(2,181)	183
Inventory	(3,929)	5,246	2,154
Other assets	(1,843)	(2,082)	(816)
Accounts payable	9,717	8,130	11,015
Accrued expenses	1,421	1,495	3,385
Accrued compensation	52	4,302	7,132
Deferred revenue	(2,007)	(374)	1,276
Long term liabilities	671	(430)	(430)
Net cash provided by operating activities	55,735	49,157	40,641
Cash flows from investing activities:
Additions of property and equipment	(13,011)	(12,597)	(5,038)
Purchase of Nekton Research, LLC, net of cash received			(2,500)
Purchases of investments	(9,189)	(30,461)	(5,000)
Sales of investments	5,000	21,500	0
Net cash used in investing activities	(17,200)	(21,558)	(12,538)
Cash flows from financing activities:
Income tax withholding payment associated with restricted stock vesting	(928)	(284)	(76)
Proceeds from stock option exercises	13,401	6,590	738
Tax benefit of excess stock-based compensation deductions	6,917	2,622	2,239
Net cash provided by financing activities	19,390	8,928	2,901
Net increase in cash and cash equivalents	57,925	36,527	31,004
Cash and cash equivalents, at beginning of period	108,383	71,856	40,852
Cash and cash equivalents, at end of period	166,308	108,383	71,856
Supplemental disclosure of cash flow information:
Cash paid for income taxes	$ 8,046	$ 17,807	$ 1,127