Summary of Significant Accounting Policies - Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value
Total assets measured at fair value	$ 18,611	$ 23,478
Level 1
Fair Value
Total assets measured at fair value	18,611	23,478
Money market funds
Fair Value
Money market funds	18,611	23,478
Money market funds \| Level 1
Fair Value
Money market funds	$ 18,611	$ 23,478

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant