Note 20 - Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Quarterly Financial Information [Table Text Block]

	Three Months Ended
	December 31, 2017		September 30, 2017		June 30, 2017		March 31, 2017
	(in thousands, except per share amounts)
Revenue	$	129,430	$	128,939	$	112,198	$	100,362
Cost of revenue		58,269		58,083		50,773		45,520
Gross profit		71,161		70,856		61,425		54,842
Operating expenses:
Research and development		21,730		21,442		20,292		18,894
Selling, general and administrative		24,038		25,255		25,873		22,092
Litigation expense, net		340		327		290		286
Total operating expenses		46,108		47,024		46,455		41,272
Income from operations		25,053		23,832		14,970		13,570
Interest and other income, net		1,647		1,255		1,237		1,381
Income before income taxes		26,700		25,087		16,207		14,951
Income tax provision		14,629		1,445		1,193		474
Net income	$	12,071	$	23,642	$	15,014	$	14,477
Net income per share:
Basic	$	0.29	$	0.57	$	0.36	$	0.35
Diluted	$	0.27	$	0.54	$	0.35	$	0.33
Weighted-average shares outstanding:
Basic		41,574		41,458		41,323		41,047
Diluted		44,610		43,486		43,397		43,268
Cash dividends declared per common share	$	0.20	$	0.20	$	0.20	$	0.20

	Three Months Ended
	December 31, 2016			September 30, 2016		June 30, 2016			March 31, 2016
	(in thousands, except per share amounts)
Revenue	$	103,618		$	106,456	$	94,079		$	84,512
Cost of revenue		47,107			48,531		43,153			39,002
Gross profit		56,511			57,925		50,926			45,510
Operating expenses:
Research and development		17,974			20,472		17,876			17,321
Selling, general and administrative		21,316			22,397		21,531			17,768
Litigation expense (benefit), net		(321	)		55		(8	)		45
Total operating expenses		38,969			42,924		39,399			35,134
Income from operations		17,542			15,001		11,527			10,376
Interest and other income, net		897			780		597			543
Income before income taxes		18,439			15,781		12,124			10,919
Income tax provision		1,866			1,408		926			344
Net income	$	16,573		$	14,373	$	11,198		$	10,575
Net income per share:
Basic	$	0.41		$	0.35	$	0.28		$	0.26
Diluted	$	0.39		$	0.34	$	0.27		$	0.25
Weighted-average shares outstanding:
Basic		40,739			40,590		40,387			40,028
Diluted		42,404			41,895		41,716			41,646
Cash dividends declared per common share	$	0.20		$	0.20	$	0.20		$	0.20