Accrued Expenses - Summary of accrued expenses (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Accounts Payable and Accrued Liabilities [Abstract]
Accrued payroll and compensation related costs	$ 708,495	$ 1,687,965
Accrued restructuring costs	144,489	109,978
Accrued dealer commissions and customer rebates	1,097,498	132,850
Other accrued liabilities	1,877,563	1,242,205
Total	$ 3,828,045	$ 3,172,998