Equity Method Accounting for Common Stock of OncoCyte, at fair value (Details) - OncoCyte [Member] - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		2 Months Ended	3 Months Ended		9 Months Ended
		Feb. 16, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Feb. 17, 2017
Schedule of Equity Method Investments [Line Items]
Common stock, outstanding (in shares)								14.7
Fair value on investment			$ 110,800		$ 110,800			$ 71,200
Price per share on NYSE American (in dollars per share)			$ 7.55		$ 7.55		$ 5.20	$ 4.85
Unrealized gains on equity method investment			$ 34,500		$ 39,600
Condensed Statements of Operations (unaudited) [Abstract]
Research and development expense	[1]	$ 798	1,836	$ 1,363	5,667	$ 4,246
General and administrative expense	[1]	377	4,289	1,063	7,447	3,145
Sales and marketing expense	[1]	213	710	156	1,843	655
Loss from operations	[1]	(1,388)	(6,835)	(2,582)	(14,957)	(8,046)
Net loss	[1]	$ (1,392)	$ (6,906)	$ (2,595)	$ (15,415)	$ (8,065)

[1] The condensed unaudited statements of operations information included in the table above for the period January 1, 2017 through February 16, 2017, and for the three and nine months ended September 30, 2016, reflects OncoCyte results of operations included in BioTime's condensed consolidated statements of operations for the three and nine months ended September 30, 2017 and 2016, as applicable, respectively, after intercompany eliminations. The information for OncoCyte for the period from February 17, 2017 through September 30, 2017 is not included in BioTime's condensed consolidated statements of operations for the three and nine months ended September 30, 2017, due to the OncoCyte Deconsolidation on February 17, 2017.