Asset Contribution Agreement (Details) (USD $)	0 Months Ended	12 Months Ended
	Oct. 01, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Asset Contribution Agreement [Line Items]
Common shares, par value (in dollars per share)		$ 0	$ 0
Number of warrants issued (in shares)		8,000,000
Number of warrants to be issued by Asterias to Series A common shareholders (in shares)		8,000,000
Exercise price of warrant (in dollars per share)	$ 5.00
Proceeds from issuance of common shares	$ 5,000,000	$ 25,938,558	$ 1,131,279	$ 0
Transaction costs allocated to issuance of equity		541,800
Intangible assets, useful life		10 years
Weighted-average assumptions [Abstract]
BioTIme common shares, at fair value		34,985,163	0	0
BioTime Warrants, at fair value		18,276,406	0	0
Common [Member]
Asset Contribution Agreement [Line Items]
Market value of BioTime common stock (in dollars per share)	$ 3.93
Common Class A [Member]
Asset Contribution Agreement [Line Items]
Common shares, par value (in dollars per share)		$ 0.0001
Common Class B [Member]
Asset Contribution Agreement [Line Items]
Common shares, par value (in dollars per share)		$ 0.0001
Warrants [Member]
Weighted-average assumptions [Abstract]
Expected term	5 years
Risk-free interest rate (in hundredths)	1.42%
Dividend yield (in hundredths)	0.00%
Expected volatility (in hundredths)	77.63%
Asterias Biotherapeutics [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)		8,902,077
Number of warrants issued (in shares)		8,000,000
Exercise price of warrant (in dollars per share)		$ 5.00
Warrant expiration term		5 years
Amount of contribution from investor		5,000,000
Weighted-average assumptions [Abstract]
Asterias Series B shares	52,164,568
Warrants to purchase Asterias Series B shares	2,012,481
Excess of contributed asset's value over consideration	4,800,063
Total consideration issued	58,977,112
BioTIme common shares, at fair value	34,985,163
BioTime Warrants, at fair value	18,276,406
Cancellation of outstanding obligation to BioTime	5,000,000
Investment in affiliates, at cost	415,543
Geron asset acquisition related transaction costs paid by BioTime	300,000
Total assets transferred	58,977,112
Asterias Biotherapeutics [Member] | Common Class B [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)		21,773,340
Number of warrants issued (in shares)		3,150,000
Exercise price of warrant (in dollars per share)		$ 5.00
Warrant expiration term		3 years
Fair value of shares issued (in dollars per share)		$ 2.40
Weighted-average assumptions [Abstract]
Expected term		3 years
Risk-free interest rate (in hundredths)		0.63%
Dividend yield (in hundredths)		0.00%
Expected volatility (in hundredths)		69.62%
OrthoCyte Corporation [Member]
Asset Contribution Agreement [Line Items]
Percentage of subsidiary stock contributed (in hundredths)		10.00%
Cell Cure Neurosciences, Ltd. [Member]
Asset Contribution Agreement [Line Items]
Percentage of subsidiary stock contributed (in hundredths)		6.00%
Geron [Member]
Weighted-average assumptions [Abstract]
Total consideration issued	34,917,532
Asterias Series A shares, net of issuance cost of $541,800	15,121,222
Obligation to distribute BioTIme Warrants	18,276,406
Transaction and other costs	1,519,904
Patents and other intellectual property rights related to hES cells, asset contribution agreement	29,017,009
Deferred tax liability arising from difference in book versus tax basis on Geron intangible assets acquired	(11,588,243)
IPR&D expensed upon acquisition	17,458,766
Total assets and in-process research and development acquired	$ 34,917,532
Geron [Member] | Common Class A [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)		6,537,779
Royalty rate on net sales of products (in hundredths)		4.00%
Romulus Films, Ltd. [Member] | Common Class B [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)	2,136,000
Number of warrants issued (in shares)	350,000