Acquisition of ES Cell International Pte Ltd (Details) (ES Cell International Pte., Ltd. [Member], USD $)	0 Months Ended	12 Months Ended
	May 03, 2010	Dec. 31, 2012
ES Cell International Pte., Ltd. [Member]
Business Acquisition [Line Items]
Date of acquisition		May 03, 2010
Common shares issued as part of acquisition of ES International Pte Ltd. (in shares)	1,383,400
Additional common shares purchased (in shares)	300,000
Exercise price (in dollars per share)	$ 10
Number of clinical grade human embryonic stem cell lines produced		6
Intangible assets, useful life		10 years
Components of the purchase price [Abstract]
BioTime common shares	$ 11,011,864
BioTime warrants	1,778,727
Cash	80,000
Total purchase price	12,870,591
Assets acquired and liabilities assumed [Abstract]
Cash	222,802
Prepaid and other current assets	65,015
Property and equipment	96,677
Equity investment in Cell Cure Neurosciences	2,766,400
Intangible assets, patents	9,937,529
Current liabilities	(217,832)
Net assets acquired	$ 12,870,591
Fair value share issued (in dollars per share)	$ 7.96
Expected term	4 years
Risk-free interest rates (in hundredths)	2.015%
Expected dividend yield (in hundredths)	0.00%
Expected volatility (in hundredths)	118.20%
Stock price (in dollars per share)	$ 7.96
Exercise price (in dollars per share)	$ 10