Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net sales	$ 105,247	$ 98,497	$ 316,927	$ 301,251
Cost of sales	23,717	19,880	69,475	64,533
Gross profit	81,530	78,617	247,452	236,718
Sales and marketing	47,493	41,717	146,496	132,582
General and administrative	18,068	19,272	56,759	54,822
Research and development	6,935	6,858	21,246	21,294
Charges related to U.S. Government resolutions		1,499		14,369
Operating income	9,034	9,271	22,951	13,651
Interest income (expense), net	(15)	471	106	320
Other income (expense), net	479	(634)	(3,284)	1,346
Income before income taxes	9,498	9,108	19,773	15,317
Income tax benefit (expense)	(6,150)	1,276	(13,998)	(6,703)
Net income from continuing operations	3,348	10,384	5,775	8,614
Discontinued operations (Note 6)
Income (loss) from discontinued operations	65	(1,018)	(1,762)	(3,580)
Income tax benefit	43	530	642	1,258
Net income (loss) from discontinued operations	108	(488)	(1,120)	(2,322)
Net income	$ 3,456	$ 9,896	$ 4,655	$ 6,292
Net income (loss) per common share—basic
Net income from continuing operations	$ 0.18	$ 0.57	$ 0.32	$ 0.47
Net income (loss) from discontinued operations	0.01	(0.02)	(0.06)	(0.13)
Net income per common share—basic	0.19	0.55	0.26	0.34
Net income (loss) per common share—diluted
Net income from continuing operations	0.18	0.56	0.31	0.46
Net income (loss) from discontinued operations	0.01	(0.02)	(0.06)	(0.12)
Net income per common share—diluted	$ 0.19	$ 0.54	$ 0.25	$ 0.34
Weighted average number of common shares:
Basic	18,180,845	18,091,650	18,071,093	18,238,533
Diluted	18,572,791	18,382,118	18,394,542	18,569,861
Other comprehensive income, before tax
Unrealized gain (loss) on derivative instrument		$ (3)		$ 124
Unrealized gain (loss) on debt securities		4,703	$ (3,220)	843
Reclassification adjustment for loss on debt securities in net income			5,585
Currency translation adjustment	$ 1,111	820	3,993	1,471
Other comprehensive income before tax	1,111	5,520	6,358	2,438
Income tax related to items of other comprehensive loss		(1,694)	(900)	(354)
Other comprehensive income, net of tax	1,111	3,826	5,458	2,084
Comprehensive income	$ 4,567	$ 13,722	$ 10,113	$ 8,376