Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net income	$ 33,397	$ 39,390
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,153	9,049
Stock-based compensation	1,992	8,370
Net gain on disposals and impairments of assets	(58)	(12)
Excess tax benefits from stock-based compensation	(2,837)	(4,120)
Deferred income taxes	4,072	(2,431)
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	2,541	3,055
Inventories	1,769	(2,450)
Income taxes	(3,084)	3,614
Prepaid expenses and other assets	(3,933)	(2,474)
Accounts payable	(1,708)	202
Customer prepayments	(2,857)	(1,892)
Accrued compensation and benefits	(4,802)	(9,085)
Other taxes and withholding	(1,156)	(920)
Warranty liabilities	(571)	(453)
Other accruals and liabilities	(775)	3,390
Net cash provided by operating activities	36,143	43,233
Cash flows from investing activities:
Purchases of property and equipment	(37,096)	(22,499)
Proceeds from sales of property and equipment	23,463	10,018
Investments in marketable debt securities	(16,504)	(45,351)
Acquisition of business	(15,500)	0
Investment in non-marketable equity securities	(3,000)	0
Proceeds from sales of property and equipment	117	30
Net cash used in investing activities	(48,520)	(57,802)
Cash flows from financing activities:
Repurchases of common stock	(22,031)	(14,023)
Proceeds from issuance of common stock	6,595	1,937
Net decrease in short-term borrowings	(4,750)	(3,349)
Excess tax benefits from stock-based compensation	2,837	4,120
Debt issuance costs	0	(47)
Net cash used in by financing activities	(17,349)	(11,362)
Net decrease in cash and cash equivalents	(29,726)	(25,931)
Cash and cash equivalents, at beginning of period	87,915	116,255
Cash and cash equivalents, at end of period	$ 58,189	$ 90,324