Enterprise-Wide Disclosures - Schedule of Geographic Area Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017
Total revenues		$ 4,988		$ 3,458	[1]
Long-lived assets		5,835	[2]	5,533
United States [Member]
Total revenues		1,804		1,651	[1]
Foreign [Member]
Total revenues	[3]	3,184		1,807	[1]
Long-lived assets	[4]	3,797	[2]	2,787
Domestic [Member]
Long-lived assets		$ 2,038	[2]	$ 2,746

[1] Amounts recognized prior to adoption of Topic 606 have not been adjusted under the Topic 606 modified retrospective transition method.

[2] Reflects the effect of the AgeX Deconsolidation.

[3] Foreign revenues are primarily generated from grants in Israel.

[4] Assets in foreign countries principally include laboratory equipment and leasehold improvements in Israel.