Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended														0 Months Ended	1 Months Ended	12 Months Ended		0 Months Ended	1 Months Ended			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2013 4.50% Convertible senior notes	Dec. 31, 2012 4.50% Convertible senior notes	Dec. 31, 2011 4.50% Convertible senior notes	Dec. 31, 2013 Stock Options and Warrants	Dec. 31, 2012 Stock Options and Warrants	Dec. 31, 2011 Stock Options and Warrants	Dec. 31, 2013 Restricted Stock	Dec. 31, 2012 Restricted Stock	Dec. 31, 2011 Restricted Stock	Jul. 24, 2013 4.50% Convertible senior notes (due 2014)	Nov. 30, 2009 4.50% Convertible senior notes (due 2014)	Dec. 31, 2013 4.50% Convertible senior notes (due 2014)	Dec. 31, 2012 4.50% Convertible senior notes (due 2014)	Jul. 24, 2013 4.25% Convertible Senior Notes (due 2018)	Jul. 24, 2013 4.25% Convertible Senior Notes (due 2018)	Dec. 31, 2013 4.25% Convertible Senior Notes (due 2018)	Dec. 31, 2012 4.25% Convertible Senior Notes (due 2018)	Dec. 31, 2013 Molds and tools
Significant Accounting Policies [Line Items]
Reserve for sales returns and allowances	$ 31,374,000	$ 34,373,000
Decrease reserve for sales returns and allowances	(2,999,000)	(9,067,000)	15,062,000
Convertible senior note payable, fair value																	37,700,000	107,900,000			97,400,000
Debt instrument, interest rate																4.50%	4.50%	4.50%	4.25%	4.25%	4.25%	4.25%
Debt instrument, maturity year																	2014	2014			2018	2018
Property and equipment useful life																							2 years
Depreciation expense	11,800,000	13,600,000	13,900,000
Advertising expenses	10,100,000	18,800,000	15,500,000
Discount on invoiced amount of products				1.00%	6.00%
Stock option expense
Restricted stock expense	1,085,000	1,122,000	1,594,000
Potentially dilutive securities excluded from computation of diluted earnings per common share						10,037,523	6,577,727	6,334,621	1,627,144	1,634,644	171,119	111,195	93,933
Debt discount																13,700,000	13,700,000
Long term debt, face amount																100,000,000	100,000,000		100,000,000	100,000,000
Debt instrument repurchase amount															61,000,000		61,000,000
Repurchase of related equity component																	2,800,000
Unamortized equity component																	902,000	5,082,000
Debt discount written off amount																	2,200,000
Debt issuance cost written off amount																	600,000
Debt instrument, maturity date	Apr. 02, 2013															Nov. 01, 2014	Nov. 01, 2014		Aug. 01, 2018
Debt instrument, interest rate																	7.30%
Frequency of interest payment																Semi-annually			Semi-annually
Conversion rate in share per $1000 principal amount of notes																63.2091			114.3674	114.3674
Debt instrument, conversion rate																$ 15.82			$ 8.74	$ 8.74
Net proceeds from debt instrument															96,000,000					100,000,000
Long term debt, fair value																	$ 37,700,000	$ 107,900,000			$ 97,400,000