Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating Activities
Net income	$ 160,127	$ 109,910
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	21,804	15,702
Stock-based compensation	3,282	4,308
Gain on disposal of property, plant and equipment	(43)	(1,083)
Other non-cash adjustments	(365)	(226)
Changes in operating assets and liabilities:
Accounts receivable	(26,988)	(157,117)
Inventories	(17,119)	(8,994)
Prepaid expenses and other assets	949	(6,878)
Accounts payable	32,943	14,907
Accrued expenses and other liabilities	13,175	10,763
Income taxes receivable/payable	2,227	466
Net cash provided by (used in) operating activities	189,992	(18,242)
Investing Activities
Expenditures for property, plant and equipment	(66,606)	(94,831)
Proceeds from sales of property, plant and equipment	45	1,314
Net cash used in investing activities	(66,561)	(93,517)
Financing Activities
Borrowings under line of credit		286,000
Principal payments under line of credit		(236,500)
Repurchases of common stock	(247,921)	(54,832)
Proceeds from employee stock purchase and option plans	951	860
Financing costs	(866)
Net cash used in financing activities	(247,836)	(4,472)
Net decrease in cash and cash equivalents	(124,405)	(116,231)
Cash and cash equivalents, beginning of period	141,053	121,701
Cash and cash equivalents, end of period	16,648	5,470
Supplemental Disclosure:
Cash paid for interest, net of capitalized interest	0	0
Cash paid for income taxes, net	$ 48,915	$ 36,457