Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Cash flows from operating activities:
Net income	$ 24,292	$ 23,683
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	31,089	31,177
Stock-based compensation	6,742	7,876
Net loss on disposals and impairments of assets	15	2
Deferred income taxes	7,212	4,974
Changes in operating assets and liabilities:
Accounts receivable	(2,753)	(4,781)
Inventories	(5,943)	5,170
Income taxes	(19,075)	(14,532)
Prepaid expenses and other assets	8,242	2,110
Accounts payable	(4,859)	11,858
Customer prepayments	369	19,518
Accrued compensation and benefits	(9,944)	9,834
Other taxes and withholding	(2,608)	(6,032)
Other accruals and liabilities	(3,648)	(2,050)
Net cash provided by operating activities	29,131	88,807
Cash flows from investing activities:
Purchases of property and equipment	(21,341)	(27,132)
Proceeds from sales of property and equipment	70	0
Net cash used in investing activities	(21,271)	(27,132)
Cash flows from financing activities:
Repurchases of common stock	(142,940)	(80,094)
Net increase in short-term borrowings	133,253	3,098
Proceeds from issuance of common stock	1,596	2,654
Debt issuance costs	(1,013)	(10)
Net cash used in financing activities	(9,104)	(74,352)
Net decrease in cash, cash equivalents and restricted cash	(1,244)	(12,677)
Cash, cash equivalents and restricted cash, at beginning of period	3,651	14,759
Cash, cash equivalents and restricted cash, at end of period	$ 2,407	$ 2,082