Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Statement of Cash Flows [Abstract]
Income taxes paid	$ 34,181	$ 23,778	$ 9,732
Interest paid	81	113	44
Capital lease obligations incurred	0	83	466
Purchases of property and equipment included in accounts payable	3,817	1,486	965
Cash flows from operating activities:
Net income	78,094	60,478	31,568
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	20,401	13,543	14,626
Stock-based compensation	10,306	4,971	3,962
Net loss on disposals and impairments of assets	115	98	251
Excess tax benefits from stock-based compensation	(6,446)	(2,190)	(1,358)
Deferred income taxes	3,499	2,839	2,352
Changes in operating assets and liabilities:
Accounts receivable	(2,705)	(3,935)	718
Inventories	(10,713)	(5,204)	(4,001)
Income taxes	4,299	4,445	6,647
Prepaid expenses and other assets	(2,382)	(1,976)	1,579
Accounts payable	7,114	6,913	3,995
Customer prepayments	1,665	585	1,707
Accrued compensation and benefits	(8,108)	5,167	11,471
Other taxes and withholding	765	1,944	53
Warranty liabilities	(1,454)	566	(1,398)
Other accruals and liabilities	6,176	2,802	(765)
Net cash provided by operating activities	100,626	91,046	71,407
Cash flows from investing activities:
Purchases of property and equipment	(51,593)	(23,527)	(7,349)
Investments in marketable debt securities	(86,803)	(40,021)	0
Proceeds from maturities of marketable debt securities	26,249	10,000	0
Proceeds from sales of property and equipment	45	11	10
Increase in restricted cash	0	(2,650)	0
Net cash used in investing activities	(112,102)	(56,187)	(7,339)
Cash flows from financing activities:
Repurchases of common stock	(34,892)	(371)	(1,391)
Excess tax benefits from stock-based compensation	6,446	2,190	1,358
Net increase (decrease) in short-term borrowings	6,494	(795)	(1,074)
Proceeds from issuance of common stock	5,138	4,356	1,014
Debt issuance costs	(50)	0	(143)
Net cash (used in) provided by financing activities	(16,864)	5,380	(236)
Net (decrease) increase in cash and cash equivalents	(28,340)	40,239	63,832
Cash and cash equivalents, at beginning of period	116,255	76,016	12,184
Cash and cash equivalents, at end of period	$ 87,915	$ 116,255	$ 76,016