Accrued Expenses and Other Current Liabilities (Details) - Accrued expenses and other current liabilities (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Dec. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Accrued expenses and other current liabilities [Abstract]
Accrued salaries and benefits	$ 1,134	$ 1,232
Warrant liability	1,647	939
Liability for consigned precious metals	478	832
Accrued legal settlement and related expenses		616
Accrued severance and other charges	254	530	530
Accrued warranty	485	453		539	665
Other	1,688	1,400
Accrued expenses and other current liabilities	$ 5,686	$ 6,002