Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Cash flows from operating activities:
Net income	$ 51,417	$ 50,519	$ 67,974
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	57,172	47,630	39,809
Stock-based compensation	11,961	10,290	6,798
Net loss on disposals and impairments of assets	27	190	492
Excess tax benefits from stock-based compensation	(517)	(2,182)	(1,163)
Deferred income taxes	(1,640)	11,924	(311)
Gain on sale of non-marketable equity securities	0	(6,891)	0
Changes in operating assets and liabilities, net of effect of acquisition:
Accounts receivable	9,297	(9,259)	(4,717)
Inventories	11,574	(33,065)	(13,383)
Income taxes	25,119	(13,943)	(4,314)
Prepaid expenses and other assets	(2,195)	8,680	(9,973)
Accounts payable	(4,965)	19,130	14,340
Customer prepayments	(25,266)	22,735	13,334
Accrued compensation and benefits	2,808	(17,493)	17,735
Other taxes and withholding	2,723	135	2,584
Other accruals and liabilities	14,130	19,542	15,263
Net cash provided by operating activities	151,645	107,942	144,468
Cash flows from investing activities:
Purchases of property and equipment	(57,852)	(85,586)	(76,594)
Proceeds from marketable debt securities	21,053	127,664	54,506
Investments in marketable debt securities	(5,968)	(29,299)	(90,349)
Proceeds from sales of property and equipment	92	72	5
Acquisition of business	0	(70,018)	0
Proceeds from (investment in) non-marketable equity securities	0	12,891	(1,500)
Increase in restricted cash	0	0	(500)
Net cash used in investing activities	(42,675)	(44,276)	(114,432)
Cash flows from financing activities:
Repurchases of common stock	(126,693)	(100,201)	(46,492)
Net increase in short-term borrowings	5,932	1,097	6,192
Proceeds from issuance of common stock	2,298	2,976	2,873
Excess tax benefits from stock-based compensation	517	2,182	1,163
Debt issuance costs	(409)	(721)	0
Net cash used in financing activities	(118,355)	(94,667)	(36,264)
Net decrease in cash and cash equivalents	(9,385)	(31,001)	(6,228)
Cash and cash equivalents, at beginning of period	20,994	51,995	58,223
Cash and cash equivalents, at end of period	11,609	20,994	51,995
Supplemental Cash Flow Information [Abstract]
Income taxes (received) paid	(653)	26,681	38,474
Interest paid	608	96	49
Purchases of property and equipment included in accounts payable	$ 5,517	$ 5,051	$ 5,802