Accrued Expenses and Other Current Liabilities (Details) - Accrued expenses and other current liabilities (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
Accrued Expenses And Other Current Liabilities [Abstract]
Accrued salaries and benefits	$ 1,115	$ 1,146
Warrant liability	910	939	910	10
Liability for consigned precious metals	534	832
Accrued legal settlement and related expenses		616
Accrued severance and other charges	669	530
Accrued warranty	469	453	569	665
Other	1,752	1,343
Accrued expenses and other current liabilities	$ 5,449	$ 5,859