Equity Method Accounting for Common Stock of OncoCyte, at fair value (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		2 Months Ended	3 Months Ended		6 Months Ended
		Feb. 16, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2017	Feb. 17, 2017	Dec. 31, 2016	May 13, 2016
Asterias Biotherapeutics, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Common stock, outstanding (in shares)										21.7
Fair value on investment			$ 77,200		$ 77,200				$ 100,000
Price per share on NYSE MKT (in dollars per share)			$ 3.55		$ 3.55		$ 3.40		$ 4.60
Condensed Statements of Operations (unaudited) [Abstract]
Loss from operations	[1]	$ (13,944)	$ (8,533)	$ (7,074)	$ (17,640)	$ (18,166)
Net loss	[1]	(13,113)	(8,728)	(5,159)	(15,015)	(15,496)
OncoCyte [Member]
Schedule of Equity Method Investments [Line Items]
Common stock, outstanding (in shares)								14.7
Fair value on investment			$ 76,300		$ 76,300			$ 71,200
Price per share on NYSE MKT (in dollars per share)			$ 5.20		$ 5.20		$ 5.95	$ 4.85
Unrealized gains (loss) on equity method investment			$ (11,000)		$ 5,100
Condensed Statements of Operations (unaudited) [Abstract]
Research and development expense	[2]	798	1,997	1,195	3,881	2,884
General and administrative expense	[2]	377	1,115	1,067	3,158	2,081
Sales and marketing expense	[2]	213	477	270	1,132	499
Loss from operations	[2]	(1,388)	(3,589)	(2,532)	(8,121)	(5,464)
Net loss	[2]	$ (1,392)	$ (3,804)	$ (2,543)	$ (8,509)	$ (5,471)

[1] The condensed unaudited statement of operations information included in the table above reflects Asterias' results of operations for the three and six months ended June 30, 2017 and 2016. Although the periods shown are provided for comparative purposes only, the condensed results of operations of Asterias shown for the three and six months ended June 30, 2017 were not included in BioTime's condensed consolidated statements of operations. The unaudited results of operations of Asterias for the period January 1, 2016 through May 12, 2016 only are included in the unaudited condensed consolidated results of BioTime for the three and six months ended June 30, 2016 due to the Asterias Deconsolidation on May 13, 2016.

[2] 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 six months ended June 30, 2016, reflects OncoCyte results of operations included in BioTime's condensed consolidated statements of operations for the three and six months ended June 30, 2017 and 2016, as applicable, respectively, after intercompany eliminations. The information for OncoCyte shown for the period from February 17, 2017 through June 30, 2017 is not included in BioTime's condensed consolidated statements of operations for the three and six months ended June 30, 2017, due to the OncoCyte Deconsolidation on February 17, 2017.