Accrued Expenses and Other Current Liabilities (Details) - Accrued expenses and other current liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accrued expenses and other current liabilities [Abstract]
Accrued salaries and benefits	$ 1,232	$ 1,347
Warrant liability	939	10
Liability for consigned precious metals	832	694
Accrued legal settlement and related expenses	616
Accrued severance and other charges	530	490
Accrued warranty	453	665	645
Sales tax payable	206	216
Other	1,194	1,092
Accrued expenses and other current liabilities	$ 6,002	$ 4,514