Summary of Significant Accounting Policies - Sales Returns (Details) (USD $)	3 Months Ended			12 Months Ended
	Dec. 31, 2012	Mar. 31, 2012	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Movement in Valuation Allowances and Reserves [Roll Forward]
Provision for sales returns	$ 500,000	$ 100,000	$ 100,000	$ (625,452)	$ 358,287	$ 1,781,617
Allowance for sales returns [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year		1,429,597		1,429,597	2,663,648	1,883,623
Provision for sales returns				625,452	(358,287)	(1,781,617)
Sales returns				(320,280)	(1,592,338)	(1,001,592)
Balance at end of year	483,865			483,865	1,429,597	2,663,648
Allowance for sales returns [Member] | Current period sales [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Provision for sales returns				0	(52,487)	(934,190)
Sales returns				0	0	(62,061)
Allowance for sales returns [Member] | Prior period sales [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Provision for sales returns				625,452	(305,800)	(847,427)
Sales returns				(320,280)	(1,592,338)	(939,531)
Allowance for sales returns [Member] | Crinone [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Sales returns				$ 0	$ 0	$ 0