Selected Balance Sheet Components - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2018	[1]	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Intangible assets	$ 625		$ 2,419
Accumulated amortization	(625)		(1,673)
Intangible assets, net			$ 746

[1] As part of OncoCyte's impairment assessment of certain intangible assets, OncoCyte determined that those assets were impaired as of June 30, 2018 and, accordingly, OncoCyte recorded a noncash charge of $625,000 representing the net book value of those assets as of that date, and included that charge in research and development expenses for the year ended December 31, 2018. The impairment was primarily due to OncoCyte's decision to discontinue any further utilization of the underlying patents, patent applications and licenses since those assets are for therapeutic use and not for diagnostic use, as OncoCyte continues to devote all of its research and development resources and commercialization efforts to cancer diagnostic tests. Research and development expenses for the year ended December 31, 2018 include $121,000 in amortization expense related to those intangible assets recorded prior to the impairment charge. For the year ended December 31, 2017, research and development expenses include $242,000 of amortization of intangible assets.