Selected Balance Sheet Components (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accrued expenses and other current liabilities [Abstract]
Accrued bonuses and payroll related expenses	$ 636	$ 549
Other accrued expenses	406	248
Accrued expenses and other current liabilities	$ 1,042	797
Finite-Lived Intangible Assets [Line Items]
Intangible assets useful life	10 years
Amortization expense	$ 242	242	$ 242
Intangible assets, net [Abstract]
Intangible assets	2,419	2,419
Accumulated amortization	(1,673)	(1,431)
Intangible assets, net	746	988
Equipment and furniture, net [Abstract]
Equipment and furniture	1,479	1,007
Accumulated depreciation	(657)	(319)
Equipment and furniture, net	822	688
Depreciation expense	338	145	$ 41
Laboratory equipment value	$ 381	$ 626

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

Name:	us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.