CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 32,234	$ 55,735	$ 170,851
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	33,303	35,203	34,930
Amortization of intangibles	1,279	2,173	2,415
Loss on disposal of property and equipment	240	100	1,371
Stock-based compensation expense	35,076	28,528	22,364
Amortization of premium (accretion of discount) on marketable securities	(1,637)	(351)	3,292
Deferred income taxes	(8,352)	(9,247)	(2,566)
Increase (decrease) in accounts receivable allowance for credit losses	(245)	(454)	690
Change in operating assets and liabilities:
Accounts receivable	(12,253)	6,616	19,867
Inventories	(2,448)	(27,744)	(36,154)
Prepaid expenses and other assets	4,001	(1,183)	7,343
Accounts payable	3,454	(5,435)	(3,836)
Taxes payable and accrued liabilities	(3,471)	(18,182)	(5,224)
Net cash provided by operating activities	81,181	65,759	215,343
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(17,286)	(20,884)	(39,211)
Proceeds from sale of property and equipment	0	0	1,202
Purchases of marketable securities	(105,716)	(191,211)	(55,820)
Proceeds from sales and maturities of marketable securities	106,602	197,942	172,165
Acquisition (Note 15)	(9,520)	0	0
Net cash provided by (used in) investing activities	(25,920)	(14,153)	78,336
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	5,700	6,237	6,162
Repurchase of common stock	(27,881)	(55,278)	(311,094)
Payments of dividends to stockholders	(46,037)	(44,008)	(41,492)
Net cash used in financing activities	(68,218)	(93,049)	(346,424)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(12,957)	(41,443)	(52,745)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	63,929	105,372	158,117
CASH AND CASH EQUIVALENTS AT END OF PERIOD	50,972	63,929	105,372
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	2,693	2,747	1,082
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes, net	$ 4,784	$ 13,769	$ 17,880