Income Taxes (Details Narrative) - USD ($) $ in Thousands				12 Months Ended
	Dec. 22, 2017	Feb. 17, 2017	May 13, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jun. 06, 2017
Repatriation tax foreign earnings in federal income	$ 227
Net deferred tax assets				$ 8,900
Federal income tax rate				34.00%	34.00%	34.00%
Net operating loss carryforwards for federal tax purposes				$ 162,600
Foreign net operating loss carryforwards				65,200
Net operating loss carryforwards for state tax purposes				95,000
Deferred income tax benefit						$ (4,516)
Deferred income tax expense (benefit), federal						4,800
Deferred income tax expense (benefit), state taxes						$ 290
Net operating loss carryforwards change in ownership control				50.00%
Federal and State [Member]
Net operating losses expiration date				between 2018 and 2036
Federal [Member]
Net operating losses expiration date				between 2018 and 2036
Tax credit carryforwards				$ 3,300
State Tax [Member]
Tax credit carryforwards				3,300
LifeMap Sciences, Ltd. [Member]
Net operating loss carryforwards for federal tax purposes				17,600
OncoCyte Deconsolidation [Member]
Gain on deconsolidation of asterias		$ 71,700		2,900
Asterias Deconsolidation [Member]
Gain on deconsolidation of asterias			$ 49,000	51,100	$ 34,300
LifeMap Solutions, Inc [Member]
Taxable gain on asset transfer				3,700
Federal alternative minimum tax payable				$ 22,000
LifeMap Solutions, Inc [Member] | Debt Conversion Agreement [Member]
Iintercompany indebtedness							$ 8,700
Net operating loss carryforwards							$ 3,300
Maximum [Member]
Deferred tax assets and liabilities re-rated percentage				34.00%
Minimum [Member]
Deferred tax assets and liabilities re-rated percentage				21.00%