Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 60,081	$ 78,094	$ 60,478
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	30,811	20,401	13,543
Stock-based compensation	4,232	10,306	4,971
Net loss on disposals and impairments of assets	24	115	98
Excess tax benefits from stock-based compensation	(3,831)	(6,446)	(2,190)
Deferred income taxes	2,037	3,499	2,839
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	1,993	(2,705)	(3,935)
Inventories	(3,910)	(10,713)	(5,204)
Income taxes	4,395	4,299	4,445
Prepaid expenses and other assets	(3,169)	(2,382)	(1,976)
Accounts payable	(3,477)	7,114	6,913
Customer prepayments	198	1,665	585
Accrued compensation and benefits	(5,202)	(8,108)	5,167
Other taxes and withholding	(153)	765	1,944
Warranty liabilities	(1,236)	(1,454)	566
Other accruals and liabilities	5,312	6,176	2,802
Net cash provided by operating activities	88,105	100,626	91,046
Cash flows from investing activities:
Purchases of property and equipment	(76,811)	(51,593)	(23,527)
Proceeds from maturities of marketable debt securities	53,565	26,249	10,000
Investments in marketable debt securities	(44,170)	(86,803)	(40,021)
Acquisition of business	(15,500)	0	0
Investment in non-marketable equity securities	(4,500)	0	0
Proceeds from sales of property and equipment	117	45	11
Increase in restricted cash	0	0	(2,650)
Net cash used in investing activities	(87,299)	(112,102)	(56,187)
Cash flows from financing activities:
Repurchases of common stock	(42,072)	(34,892)	(371)
Proceeds from issuance of common stock	7,966	5,138	4,356
Net (decrease) increase in short-term borrowings	(223)	6,494	(795)
Excess tax benefits from stock-based compensation	3,831	6,446	2,190
Debt issuance costs	0	(50)	0
Net cash (used in) provided by financing activities	(30,498)	(16,864)	5,380
Net (decrease) increase in cash and cash equivalents	(29,692)	(28,340)	40,239
Cash and cash equivalents, at beginning of period	87,915	116,255	76,016
Cash and cash equivalents, at end of period	58,223	87,915	116,255
Income taxes paid	24,253	34,181	23,778
Interest paid	34	81	113
Capital lease obligations incurred	0	0	83
Purchases of property and equipment included in accounts payable	$ 3,465	$ 3,817	$ 1,486