Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 25,418	$ 20,548
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,743	15,680
Stock-based compensation	3,638	3,084
Net gain on disposals and impairments of assets	(433)	(70)
Deferred income taxes	824	1,184
Changes in operating assets and liabilities:
Accounts receivable	6,182	(2,486)
Inventories	1,568	(2,485)
Income taxes	4,208	4,762
Prepaid expenses and other assets	(5,283)	13,894
Accounts payable	5,857	123
Customer prepayments	3,452	2,412
Accrued compensation and benefits	1,750	(7,567)
Other taxes and withholding	1,254	1,662
Other accruals and liabilities	3,958	(1,485)
Net cash provided by operating activities	68,136	49,256
Cash flows from investing activities:
Purchases of property and equipment	(19,743)	(8,805)
Proceeds from sales of property and equipment	2,571	70
Net cash used in investing activities	(17,172)	(8,735)
Cash flows from financing activities:
Repurchases of common stock	(55,656)	(77,648)
Net increase in short-term borrowings	2,955	35,963
Proceeds from issuance of common stock	2,836	857
Debt issuance costs	(1,015)	(1,009)
Net cash used in financing activities	(50,880)	(41,837)
Net increase (decrease) in cash and cash equivalents	84	(1,316)
Cash and cash equivalents, at beginning of period	1,612	3,651
Cash and cash equivalents, at end of period	$ 1,696	$ 2,335