CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
REVENUE	$ 87,765,000	$ 43,572,000
COST OF SALES	15,814,000	7,458,000
Gross margin	71,951,000	36,114,000
OPERATING EXPENSES:
Research and development	15,829,000	12,357,000
Selling, general and administrative	11,969,000	10,791,000
Amortization of acquired technology and other intangible assets	5,486,000	5,491,000
Patent costs	1,770,000	1,725,000
Royalty and license expense	2,537,000	1,231,000
Total operating expenses	37,591,000	31,595,000
OPERATING INCOME	34,360,000	4,519,000
Interest income, net	2,831,000	1,271,000
Other income (expense), net	282,000	(47,000)
Interest and other income, net	3,113,000	1,224,000
INCOME BEFORE INCOME TAXES	37,473,000	5,743,000
INCOME TAX (EXPENSE) BENEFIT	(5,999,000)	216,000
NET INCOME	$ 31,474,000	$ 5,959,000
NET INCOME PER COMMON SHARE:
BASIC	$ 0.66	$ 0.13
DILUTED	$ 0.66	$ 0.13
WEIGHTED AVERAGE SHARES USED IN COMPUTING NET INCOME PER COMMON SHARE:
BASIC	46,892,914	46,783,158
DILUTED	46,931,999	46,848,798
CASH DIVIDENDS DECLARED PER COMMON SHARE	$ 0.10	$ 0.06