Sales of BioTime Common Shares by Subsidiaries (Details) (USD $)	9 Months Ended
	Sep. 30, 2014 Investor
Asterias Biotherapeutics [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares sold (in shares)	5,000,000
Number of investors	2
Proceeds from sale of BioTime stock	$ 12,500,000
Asterias Biotherapeutics [Member] | Asterias Series B Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	5,000,000
Broadwood Partners, LP [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	1,000,000
Allocation of proceeds from sale of shares and warrants	9,316,109
Broadwood Partners, LP [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Number of warrants issued (in shares)	1,000,000
Allocation of proceeds from sale of shares and warrants	$ 3,183,891
George Karfunkel [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	4,000,000
Ownership percentage (in hundredths)	5.00%
George Karfunkel [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Number of warrants issued (in shares)	4,000,000