Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 04, 2015	Mar. 29, 2014
Cash flows from operating activities:
Net income	$ 28,799	$ 16,992
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,783	9,176
Stock-based compensation	2,782	(108)
Net loss (gain) on disposals and impairments of assets	177	(2)
Excess tax benefits from stock-based compensation	(858)	(19)
Deferred income taxes	(3,415)	(1,450)
Changes in operating assets and liabilities:
Accounts receivable	1,780	(552)
Inventories	(2,469)	(4,438)
Income taxes	15,453	3,795
Prepaid expenses and other assets	(1,661)	1,030
Accounts payable	7,458	3,600
Customer prepayments	(2,591)	4,785
Accrued compensation and benefits	(8,977)	4,080
Other taxes and withholding	(58)	36
Warranty liabilities	900	185
Other accruals and liabilities	761	1,754
Net cash provided by operating activities	48,864	38,864
Cash flows from investing activities:
Purchases of property and equipment	(17,796)	(16,660)
Investments in marketable debt securities	(18,195)	(13,623)
Proceeds from maturities of marketable debt securities	16,244	10,000
Increase in restricted cash	0	(500)
Proceeds from sales of property and equipment	33	5
Net cash used in investing activities	(19,714)	(20,778)
Cash flows from financing activities:
Repurchases of common stock	(20,475)	(10,236)
Net decrease in short-term borrowings	(16,530)	(6,094)
Proceeds from issuance of common stock	1,353	411
Excess tax benefits from stock-based compensation	858	19
Net cash used in financing activities	(34,794)	(15,900)
Net (decrease) increase in cash and cash equivalents	(5,644)	2,186
Cash and cash equivalents, at beginning of period	51,995	58,223
Cash and cash equivalents, at end of period	$ 46,351	$ 60,409