Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net income	$ 71,211	$ 48,545
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	10,473	6,423
Stock-based compensation	2,226	2,176
Gain on disposal of property, plant and equipment		(98)
Other non-cash adjustments	77	77
Changes in operating assets and liabilities:
Accounts receivable	(49,825)	(202,781)
Inventories	(14,423)	(6,774)
Prepaid expenses and other assets	1,560	(809)
Accounts payable	36,605	10,494
Accrued expenses and other liabilities	(6,149)	(14,453)
Income taxes receivable/payable	22,124	14,626
Net cash provided by (used in) operating activities	73,879	(142,574)
Investing Activities
Expenditures for property, plant and equipment	(22,288)	(58,093)
Proceeds from sales of property, plant and equipment		293
Net cash used in investing activities	(22,288)	(57,800)
Financing Activities
Borrowings under line of credit		142,000
Principal payments under line of credit		(6,000)
Repurchases of common stock	(77,929)	(49,566)
Proceeds from employee stock purchase and option plans	523	460
Financing costs	(50)
Net cash (used in) provided by financing activities	(77,456)	86,894
Net decrease in cash and cash equivalents	(25,865)	(113,480)
Cash and cash equivalents, beginning of period	141,053	121,701
Cash and cash equivalents, end of period	115,188	8,221
Supplemental Disclosure:
Cash paid for interest, net of capitalized interest	0	0
Cash paid for income taxes, net	$ 1,604	$ 1,319