Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014
Cash flows from operating activities:
Net income	$ 39,837	$ 25,473
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	21,903	19,213
Stock-based compensation	5,828	2,035
Net loss on disposals and impairments of assets	184	87
Excess tax benefits from stock-based compensation	(1,945)	(720)
Deferred income taxes	(4,515)	(2,003)
Changes in operating assets and liabilities:
Accounts receivable	(825)	651
Inventories	(14,842)	(3,004)
Income taxes	4,221	(394)
Prepaid expenses and other assets	(944)	(4,355)
Accounts payable	7,879	(1,042)
Customer prepayments	(3,066)	2,695
Accrued compensation and benefits	(8,121)	9,724
Other taxes and withholding	(2,622)	(529)
Warranty liabilities	1,113	281
Other accruals and liabilities	969	1,466
Net cash provided by operating activities	45,054	49,578
Cash flows from investing activities:
Purchases of property and equipment	(38,938)	(39,766)
Investments in marketable debt securities	(19,306)	(28,405)
Proceeds from maturities of marketable debt securities	41,932	23,548
Proceeds from sales of property and equipment	41	5
Increase in restricted cash	0	(500)
Net cash used in investing activities	(16,271)	(45,118)
Cash flows from financing activities:
Repurchases of common stock	(51,629)	(21,470)
Net decrease in short-term borrowings	(7,478)	(6,192)
Proceeds from issuance of common stock	2,458	1,366
Excess tax benefits from stock-based compensation	1,945	720
Net cash used in financing activities	(54,704)	(25,576)
Net decrease in cash and cash equivalents	(25,921)	(21,116)
Cash and cash equivalents, at beginning of period	51,995	58,223
Cash and cash equivalents, at end of period	$ 26,074	$ 37,107