CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
REVENUE:
Total revenue	$ 134,000	$ 112,277
COST OF SALES	23,298	22,459
Gross margin	110,702	89,818
OPERATING EXPENSES:
Research and development	23,305	19,497
Selling, general and administrative	16,404	15,403
Amortization of acquired technology and other intangible assets	5,488	5,490
Patent costs	1,835	1,638
Royalty and license expense	112	3,284
Total operating expenses	47,144	45,312
OPERATING INCOME	63,558	44,506
Interest income, net	133	2,147
Other income, net	59	202
Interest and other income, net	192	2,349
INCOME BEFORE INCOME TAXES	63,750	46,855
INCOME TAX EXPENSE	(12,063)	(8,700)
NET INCOME	$ 51,687	$ 38,155
NET INCOME PER COMMON SHARE:
BASIC	$ 1.09	$ 0.80
DILUTED	$ 1.08	$ 0.80
WEIGHTED AVERAGE SHARES USED IN COMPUTING NET INCOME PER COMMON SHARE:
BASIC	47,267,921	47,093,033
DILUTED	47,329,704	47,122,829
CASH DIVIDENDS DECLARED PER COMMON SHARE	$ 0.20	$ 0.15
Material Sales
REVENUE:
Total revenue	$ 79,808	$ 66,575
Royalty And License Fees
REVENUE:
Total revenue	50,886	43,078
Contract Research Services
REVENUE:
Total revenue	$ 3,306	$ 2,624