Restatement of the Consolidated Financial Statements - Adjustments to Previously Filed Consolidated Income Statements (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Sales	$ 117,365	$ 107,857	$ 113,423	$ 108,936	$ 118,639	$ 111,510	$ 108,216	$ 103,606	$ 447,581	$ 441,971	$ 462,571
Cost of sales	24,944	24,384	27,547	21,378	27,300	23,126	22,755	22,346	98,253	95,527	97,093
Gross profit	92,421	83,473	85,876	87,558	91,339	88,384	85,461	81,260	349,328	346,444	365,478
Operating expenses
Sales and marketing									187,131	193,511	196,113
General and administrative									53,391	64,481	73,010
Research and development									28,577	22,861	27,958
Amortization of intangibles assets									2,298	2,550	2,413
Charges related to U.S. Government resolutions									1,295	57,141
Total operation expenses	66,808	64,668	71,578	69,638	83,165	67,417	73,102	116,860	272,692	340,544	299,494
Operating income	25,613	18,805	14,298	17,920	8,174	20,967	12,359	(35,600)	76,636	5,900	65,984
Other income and (expense)									(6,448)	(7,953)	(10,956)
Income (loss) before income taxes									70,188	(2,053)	55,028
Income tax expense									(25,138)	(14,165)	(24,031)
Net income from continuing operations, net of tax	16,009	10,574	9,870	8,597	7,652	11,300	6,579	(41,749)	45,050	(16,218)	30,997
Previously Reported [Member]
Net Sales	112,035	114,752	119,492	116,041	123,085	117,306	116,670	113,060	462,320	470,121	460,629
Cost of sales	18,504	22,373	23,676	21,939	23,239	23,854	23,186	22,340	86,492	92,619	90,461
Gross profit	93,531	92,379	95,816	94,102	99,846	93,452	93,484	90,720	375,828	377,502	370,168
Operating expenses
Sales and marketing									200,343	200,145	200,835
General and administrative									53,827	64,374	72,912
Research and development									28,577	22,861	27,958
Amortization of intangibles assets									2,098	2,350	2,213
Charges related to U.S. Government resolutions									1,973	56,463
Total operation expenses	69,050	70,846	75,251	71,671	84,035	69,853	74,088	118,217	286,818	346,193	303,918
Operating income	24,481	21,533	20,565	22,431	15,811	23,599	19,396	(27,497)	89,010	31,309	66,250
Other income and (expense)									(6,282)	(11,868)	(15,886)
Income (loss) before income taxes									82,728	19,441	50,364
Income tax expense									(28,792)	(21,181)	(22,606)
Net income from continuing operations, net of tax	14,636	13,118	13,967	12,215	11,530	12,951	10,519	(36,740)	53,936	(1,740)	27,758
Total Adjustments [Member]
Net Sales									(14,739)	(28,150)	1,942
Cost of sales									11,761	2,908	6,632
Gross profit									(26,500)	(31,058)	(4,690)
Operating expenses
Sales and marketing									(13,212)	(6,634)	(4,722)
General and administrative									(436)	107	98
Amortization of intangibles assets									200	200	200
Charges related to U.S. Government resolutions									(678)	678
Total operation expenses									(14,126)	(5,649)	(4,424)
Operating income									(12,374)	(25,409)	(266)
Other income and (expense)									(166)	3,915	4,930
Income (loss) before income taxes									(12,540)	(21,494)	4,664
Income tax expense									3,654	7,016	(1,425)
Net income from continuing operations, net of tax									(8,886)	(14,478)	3,239
Distributor Revenue [Member]
Net Sales									(14,777)	(29,135)	2,088
Cost of sales									(2,032)	(8,289)	(323)
Gross profit									(12,745)	(20,846)	2,411
Operating expenses
Sales and marketing									(6,629)	(1,216)	(275)
General and administrative									(2)
Total operation expenses									(6,631)	(1,216)	(275)
Operating income									(6,114)	(19,630)	2,686
Income (loss) before income taxes									(6,114)	(19,630)	2,686
Income tax expense									1,782	6,408	(821)
Net income from continuing operations, net of tax									(4,332)	(13,222)	1,865
Inventory Reserves [Member]
Cost of sales									5,647	3,377	2,281
Gross profit									(5,647)	(3,377)	(2,281)
Operating expenses
Operating income									(5,647)	(3,377)	(2,281)
Income (loss) before income taxes									(5,647)	(3,377)	(2,281)
Income tax expense									1,645	1,102	697
Net income from continuing operations, net of tax									(4,002)	(2,275)	(1,584)
Royalties [Member]
Cost of sales									8,190	7,713	5,386
Gross profit									(8,190)	(7,713)	(5,386)
Operating expenses
Sales and marketing									(8,190)	(7,713)	(5,386)
Total operation expenses									(8,190)	(7,713)	(5,386)
Other [Member]
Net Sales									38	985	(146)
Cost of sales									(44)	107	(712)
Gross profit									82	878	566
Operating expenses
Sales and marketing									1,607	2,295	939
General and administrative									(434)	107	98
Amortization of intangibles assets									200	200	200
Charges related to U.S. Government resolutions									(678)	678
Total operation expenses									695	3,280	1,237
Operating income									(613)	(2,402)	(671)
Other income and (expense)									(166)	3,915	4,930
Income (loss) before income taxes									(779)	1,513	4,259
Income tax expense									227	(494)	(1,301)
Net income from continuing operations, net of tax									$ (552)	$ 1,019	$ 2,958