Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Cash flows provided by operating activities:
Net income	$ 65,565	$ 18,234
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	16,996	15,945
Impairment of assets	227	1,521
Gain on disposal of property, plant and equipment	(36)
Change in right-of-use assets	1,965	1,807
Credit loss (recovery) expense	(48)	552
Stock-based compensation expense	4,957	2,566
Deferred income taxes	4,565	2,379
Changes in operating assets and liabilities:
Accounts receivable	(26,723)	(4,436)
Inventories	(30,581)	(23,856)
Prepaid expenses, income tax receivable and other current assets	(14,369)	(2,077)
Third-party production prepayments	(21,584)	1,234
Other assets		(41)
Accounts payable	36,912	14,264
Accrued expenses and other current liabilities	(16,095)	(7,579)
Change in operating lease liabilities	(2,020)	(1,489)
Other liabilities	76	(100)
Net cash provided by operating activities	19,807	18,924
Cash flows used in investing activities:
Purchases of property, plant and equipment	(39,278)	(27,394)
Proceeds from disposal of property, plant and equipment	320	35
Other investing activities	145	96
Net cash used in investing activities	(38,813)	(27,263)
Cash flows provided by financing activities:
Proceeds from exercise of stock options and sale of investment shares	6,768	2,941
Net cash paid on note payable and finance leases	(435)	(209)
Cash borrowed on line of credit		100,000
Payment of tax withholding on stock-based payment awards and investment shares	(5,951)	(1,559)
Net cash provided by financing activities	382	101,173
Change in cash and cash equivalents	(18,624)	92,834
Cash and cash equivalents at beginning of year	163,282	36,670
Cash and cash equivalents at end of period	144,658	129,504
Supplemental disclosure of cash flow information:
Income taxes paid	4	5
Cash paid for amounts included in measurement of lease liabilities
Operating cash flows from operating leases	2,602	2,097
Operating cash flows from finance leases	34	22
Financing cash flows from finance leases	364	141
Right-of-use-assets obtained in exchange for operating lease obligations		11,088
Change in purchase of property, plant and equipment in accounts payable and accrued expenses	$ (8,997)	$ (1,029)