Note 18 - Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

	Three Months Ended
	March 31, 2014			June 30, 2014		September 30, 2014			December 31, 2014
	(in thousands, except per share amounts)
Revenue	$	60,061		$	68,436	$	78,335		$	75,703
Cost of revenue		27,964			31,337		35,872			34,744
Gross profit		32,097			37,099		42,463			40,959
Operating expenses:
Research and development		15,603			13,368		14,679			14,941
Selling, general and administrative		16,109			16,853		17,006			16,787
Litigation expense (benefit), net		(8,700	)		274		332			66
Total operating expenses		23,012			30,495		32,017			31,794
Income from operations		9,085			6,604		10,446			9,165
Interest and other income, net		190			295		202			407
Income before income taxes		9,275			6,899		10,648			9,572
Income tax provision (benefit)		257			502		(573	)		712
Net income	$	9,018		$	6,397	$	11,221		$	8,860
Net income per share:
Basic	$	0.23		$	0.17	$	0.29		$	0.23
Diluted	$	0.23		$	0.16	$	0.28		$	0.22
Weighted-average shares outstanding:
Basic		38,470			38,684		38,785			38,807
Diluted		39,517			39,608		39,727			40,321
Cash dividends declared per common share	$	-		$	0.15	$	0.15		$	0.15

	Three Months Ended
	March 31, 2013			June 30, 2013			September 30, 2013			December 31, 2013
	(in thousands, except per share amounts)
Revenue	$	51,470		$	57,714		$	65,347		$	63,560
Cost of revenue		24,085			26,786			30,053			29,266
Gross profit		27,385			30,928			35,294			34,294
Operating expenses:
Research and development		12,123			12,478			12,643			12,487
Selling, general and administrative		13,258			13,793			13,891			13,683
Litigation expense (benefit), net		(301	)		(257	)		104			84
Total operating expenses		25,080			26,014			26,638			26,254
Income from operations		2,305			4,914			8,656			8,040
Interest and other income (expense), net		(10	)		218			(59	)		(57	)
Income before income taxes		2,295			5,132			8,597			7,983
Income tax provision (benefit)		(204	)		(357	)		1,187			484
Net income	$	2,499		$	5,489		$	7,410		$	7,499
Net income per share:
Basic	$	0.07		$	0.15		$	0.20		$	0.20
Diluted	$	0.07		$	0.14		$	0.19		$	0.19
Weighted-average shares outstanding:
Basic		36,259			37,053			37,910			38,328
Diluted		37,708			38,239			39,009			39,524
Cash dividends declared per common share	$	-		$	-		$	-		$	-