Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Activities
Net income	$ 226,392	$ 205,384	$ 184,626
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	54,670	50,189	44,298
Deferred income taxes	(16,407)	4,215	24,256
Loss on sale	0	0	15,423
Stock-based compensation	12,635	10,164	5,329
Loss (gain) on disposal of property, plant and equipment	2,644	3,140	(27)
Other non-cash adjustments	187	(48)	(117)
Changes in operating assets and liabilities:
Accounts receivable	(47,220)	56,921	42,513
Inventories	(100,193)	34,266	(64,454)
Prepaid expenses and other assets	(10,650)	(750)	7,925
Accounts payable	(819)	2,697	(5,595)
Accrued expenses and other liabilities	12,162	8,875	(14,385)
Income taxes receivable/payable	10,528	14,367	(23,572)
Net cash provided by operating activities	143,929	389,420	216,220
Investing Activities
Expenditures for property, plant and equipment	(232,337)	(166,089)	(176,228)
Purchased intangibles	(4,304)	0	0
Proceeds from sale of assets	0	0	7,290
Proceeds from sales of property, plant and equipment	106	0	54
Net cash used in investing activities	(236,535)	(166,089)	(168,884)
Financing Activities
Borrowings under line of credit	842,300	593,500	425,000
Principal payments under line of credit	(645,200)	(810,000)	(203,000)
Repurchases of common stock	(105,940)	(18,450)	(398,382)
Proceeds from employee stock purchase and option plans	1,282	1,223	1,742
Financing costs	(503)	30	(1,424)
Net cash provided by (used in) financing activities	91,939	(233,697)	(176,064)
Net decrease in cash and cash equivalents	(667)	(10,366)	(128,728)
Cash and cash equivalents at beginning of year	1,959	12,325	141,053
Cash and cash equivalents at end of year	1,292	1,959	12,325
Supplemental disclosures of cash flow information:
Cash paid for interest, net of capitalized interest	0	51	0
Cash paid for income taxes, net	85,171	52,340	59,934
Supplemental non-cash investing and financing disclosure:
Capital expenditures in accounts payable	$ 38,129	$ 1,332	$ 1,814