Cash and Cash Equivalents and Restricted Time Deposits (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 21,408	$ 25,116	$ 26,928
Certificate of deposit	284	272
United States [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	16,800	19,200
Foreign [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	4,600	4,600
Restricted Time Deposit [Member]
Cash and Cash Equivalents [Line Items]
Certificate of deposit	$ 300	$ 300