CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
REVENUE:
Total revenue	$ 576,429	$ 616,619	$ 553,525
COST OF SALES	135,376	127,896	114,991
Gross margin	441,053	488,723	438,534
OPERATING EXPENSES:
Research and development	130,481	117,062	99,673
Selling, general and administrative	67,387	77,886	80,372
Amortization of acquired technology and other intangible assets	15,993	17,459	21,994
Patent costs	9,356	8,329	8,160
Royalty and license expense	647	877	691
Total operating expenses	223,864	221,613	210,890
OPERATING INCOME	217,189	267,110	227,644
Interest income, net	28,166	7,811	505
Other (loss) income, net	(184)	(6,691)	98
Interest and other income, net	27,982	1,120	603
Income before income taxes	245,171	268,230	228,247
INCOME TAX EXPENSE	(42,160)	(58,169)	(44,034)
NET INCOME	$ 203,011	$ 210,061	$ 184,213
NET INCOME PER COMMON SHARE:
BASIC	$ 4.25	$ 4.41	$ 3.87
DILUTED	$ 4.24	$ 4.4	$ 3.87
WEIGHTED AVERAGE SHARES USED IN COMPUTING NET INCOME PER COMMON SHARE:
BASIC	47,559,669	47,390,352	47,296,447
DILUTED	47,622,763	47,468,507	47,365,435
CASH DIVIDEND DECLARED PER COMMON SHARE	$ 1.4	$ 1.2	$ 0.8
Material sales
REVENUE:
Total revenue	$ 322,029	$ 331,081	$ 318,623
Royalty and license fees
REVENUE:
Total revenue	238,389	267,115	219,032
Contract research services
REVENUE:
Total revenue	$ 16,011	$ 18,423	$ 15,870