Equity Method Accounting for Common Stock of Asterias, at fair value (Details) - USD ($) $ in Thousands, shares in Millions		4 Months Ended	12 Months Ended
		May 12, 2016	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014	May 13, 2016
Schedule of Equity Method Investments [Line Items]
Fair value on investment			$ 100,039		$ 0
Asterias Biotherapeutics, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Common stock, outstanding (in shares)							21.7
Fair value on investment			100,000				$ 65,700
Unrealized gains on equity method investment			34,300
Condensed Statements of Operations [Abstract]
Total revenue		$ 2,354	6,954	[1]	3,582	$ 1,224
Gross profit		2,301	6,826	[1]	3,314	1,129
Loss from operations		(13,944)	(34,123)	[1]	(21,908)	(17,461)
Net loss		$ (13,113)	(35,038)	[1]	(15,003)	$ (10,097)
Condensed Balance Sheet information [Abstract]
Current assets	[2]		36,990		29,789
Noncurrent assets	[2]		24,020		27,445
Total assets	[2]		61,010		57,234
Current liabilities	[2]		6,051		4,980
Noncurrent liabilities	[2]		12,930		7,155
Stockholders' equity	[2]		42,029		45,099
Total liabilities and stockholders' equity	[2]		$ 61,010		$ 57,234

[1] Asterias results of operations for the period from January 1, 2016 through May 12, 2016, the date immediately preceding the Asterias Deconsolidation, are included in the consolidated results of operations of BioTime for the year ended December 31, 2016 shown in the table below.

[2] The condensed balance sheet information of Asterias as of December 31, 2016, provided for informational and comparative purposes only, was not included in BioTime's consolidated balance sheet at December 31, 2016 due to the Asterias Deconsolidation on May 13, 2016. The condensed balance sheet information of Asterias as of December 31, 2015, included in the table above, was included in BioTime's consolidated balance sheet at December 31, 2015, after intercompany eliminations.