Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 108,942	$ 104,075	$ 211,680	$ 202,754
Cost of sales	23,177	22,516	45,758	44,653
Gross profit	85,765	81,559	165,922	158,101
Sales and marketing	50,471	46,043	99,003	90,865
General and administrative	20,409	18,545	38,691	35,550
Research and development	6,887	6,796	14,311	14,436
Charges related to U.S. Government resolutions		12,870		12,870
Operating income (loss)	7,998	(2,695)	13,917	4,380
Interest income (expense), net	76	(113)	121	(151)
Other income (expense), net	585	147	(3,763)	1,980
Income (loss) before income taxes	8,659	(2,661)	10,275	6,209
Income tax expense	(3,924)	(3,685)	(7,848)	(7,979)
Net income (loss) from continuing operations	4,735	(6,346)	2,427	(1,770)
Discontinued operations (Note 6)
Loss from discontinued operations	(1,300)	(1,572)	(1,827)	(2,562)
Income tax benefit	418	474	599	728
Net loss from discontinued operations	(882)	(1,098)	(1,228)	(1,834)
Net income (loss)	$ 3,853	$ (7,444)	$ 1,199	$ (3,604)
Net income (loss) per common share—basic
Net income (loss) from continuing operations	$ 0.26	$ (0.35)	$ 0.13	$ (0.10)
Net loss from discontinued operations	(0.05)	(0.06)	(0.06)	(0.10)
Net income (loss) per common share—basic	0.21	(0.41)	0.07	(0.20)
Net income (loss) per common share—diluted
Net income (loss) from continuing operations	0.26	(0.35)	0.13	(0.10)
Net loss from discontinued operations	(0.05)	(0.06)	(0.06)	(0.10)
Net income (loss) per common share—diluted	$ 0.21	$ (0.41)	$ 0.07	$ (0.20)
Weighted average number of common shares:
Basic	18,050,551	18,147,681	18,015,308	18,312,781
Diluted	18,343,038	18,147,681	18,288,050	18,312,781
Other comprehensive income, before tax
Unrealized gain on derivative instrument		$ 79		$ 127
Unrealized loss on debt securities		(3,036)	$ (3,220)	(3,860)
Reclassification adjustment for loss on debt securities in net income			5,585
Currency translation adjustment	$ 2,648	(570)	2,882	651
Other comprehensive income before tax	2,648	(3,527)	5,247	(3,082)
Income tax related to items of other comprehensive loss		1,065	(900)	1,340
Other comprehensive income, net of tax	2,648	(2,462)	4,347	(1,742)
Comprehensive income (loss)	$ 6,501	$ (9,906)	$ 5,546	$ (5,346)