CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 41,464	$ 148,036
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	26,316	26,055
Amortization of intangibles	1,630	1,871
Loss on disposal of property and equipment	86	1,162
Stock-based compensation expense	21,025	15,710
Amortization of premium on marketable securities	146	2,638
Deferred income taxes	(9,952)	(7,390)
Increase (decrease) in accounts receivable allowance for credit losses	(454)	690
Change in operating assets and liabilities:
Accounts receivable	(7,249)	24,628
Inventories	(14,826)	(20,826)
Prepaid expenses and other assets	(837)	8,428
Accounts payable	(2,882)	(5,874)
Taxes payable and accrued liabilities	(4,975)	(3,883)
Net cash provided by operating activities	49,492	191,245
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(14,741)	(33,444)
Proceeds from sale of property and equipment	0	1,202
Purchases of marketable securities	(173,015)	(27,244)
Proceeds from sales and maturities of marketable securities	161,897	161,014
Net cash provided by (used in) investing activities	(25,859)	101,528
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	6,237	6,162
Repurchase of common stock	(7,834)	(292,349)
Payments of dividends to stockholders	(32,665)	(31,229)
Net cash used in financing activities	(34,262)	(317,416)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(10,629)	(24,643)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	105,372	158,117
CASH AND CASH EQUIVALENTS AT END OF PERIOD	94,743	133,474
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	2,429	2,555
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes, net	$ 13,683	$ 17,834