Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019
Cash flows from operating activities:
Net income	$ 77,830	$ 57,752
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	46,244	46,267
Stock-based compensation	15,554	12,034
Net loss (gain) on disposals and impairments of assets	208	(409)
Deferred income taxes	3,229	(895)
Changes in operating assets and liabilities:
Accounts receivable	(12,710)	(746)
Inventories	3,807	(1,626)
Income taxes	5,103	535
Prepaid expenses and other assets	3,666	(8,065)
Accounts payable	58,547	45,051
Customer prepayments	40,795	12,758
Accrued compensation and benefits	21,376	11,763
Other taxes and withholding	4,756	5,784
Other accruals and liabilities	18,877	9,629
Net cash provided by operating activities	287,282	189,832
Cash flows from investing activities:
Purchases of property and equipment	(28,074)	(46,757)
Proceeds from sales of property and equipment	53	2,577
Purchase of intangible assets	(945)	0
Net cash used in investing activities	(28,966)	(44,180)
Cash flows from financing activities:
Repurchases of common stock	(41,923)	(139,178)
Net decrease in short-term borrowings	(220,968)	(11,270)
Proceeds from issuance of common stock	4,650	5,752
Debt issuance costs	(303)	(1,023)
Net cash used in financing activities	(258,544)	(145,719)
Net decrease in cash and cash equivalents	(228)	(67)
Cash and cash equivalents, at beginning of period	1,593	1,612
Cash and cash equivalents, at end of period	$ 1,365	$ 1,545