Selected Balance Sheet Accounts (Details 3) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accrued expenses and other current liabilities
Accrued employee-related benefits	$ 1,925	$ 2,411
Other accrued expenses	6,563	6,307
Amounts due to customers	452	438
Other current liabilities	458	507
Total other accrued expenses and other current liabilities	7,473	7,252
Total accrued expenses and other current liabilities	$ 9,398	$ 9,663