Related Party Transactions and Related Party Convertible Debt (Details)		1 Months Ended		3 Months Ended		6 Months Ended
	May. 31, 2015 USD ($) Investor $ / shares shares	Apr. 30, 2015 USD ($) Investor $ / shares	Feb. 28, 2015 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) ft² $ / shares shares	Jun. 30, 2014 USD ($) Investor shares	Jun. 30, 2015 USD ($) ft² $ / shares shares	Jun. 30, 2014 USD ($) Investor shares	Dec. 31, 2014 USD ($) shares
Related Party Transaction [Line Items]
Rent per month						$ 5,050
Area of office space (in square feet) | ft²				900		900
Proceeds from issuance of common shares						$ 0	$ 14,724,000
Principal and accumulated interest						188,000	$ 0
Carrying value of convertible notes				$ 238,000		$ 238,000		$ 60,000
Common shares, issued (in shares) | shares				83,281,000		83,281,000		83,122,000
Asterias Biotherapeutics [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Proceeds from issuance of common shares					$ 12,500,000
Shares sold (in shares) | shares					5,000,000
Number of investors | Investor					2		2
Asterias Biotherapeutics [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Proceeds from issuance of common shares					$ 11,700,000
Number of shares purchased (in shares) | shares				1,000,000	5,000,000	1,000,000	5,000,000
Asterias Biotherapeutics [Member] | Series A Common Stock [Member]
Related Party Transaction [Line Items]
Proceeds from issuance of common shares			$ 5,500,000
Shares sold (in shares) | shares			1,410,255
Stock price (in dollars per share) | $ / shares			$ 3.90
Number of shares purchased (in shares) | shares			1,025,640
Cell Cure Neurosciences, Ltd. [Member]
Related Party Transaction [Line Items]
Number of investors | Investor		2
Stated interest rate (in hundredths)		3.00%
Conversion price (in dollars per share) | $ / shares		$ 20.00
Estimated fair market value (in dollars per share) | $ / shares		$ 41.00
Principal and accumulated interest		$ 471,000
Accrued interest is payable period		3 years
Effective annual interest rate (in hundredths)		23.00%
Carrying value of convertible notes		$ 238,000
Amount of convertible note		740,000
Unamortized debt discount		502,000
Cell Cure Neurosciences, Ltd. [Member] | Convertible Notes Payable [Member]
Related Party Transaction [Line Items]
Principal and accumulated interest		188,000
Unamortized debt discount		$ 659,000
George Karfunkel [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Shares sold (in shares) | shares					4,000,000
George Karfunkel [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares) | shares					4,000,000		4,000,000
Broadwood Partners LP [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Shares sold (in shares) | shares					1,000,000
OncoCyte [Member]
Related Party Transaction [Line Items]
Proceeds from issuance of common shares	$ 3,300,000
Shares sold (in shares) | shares	100,000
Number of shares purchased (in shares) | shares	3,000,000
Number of investors | Investor	2
Stated interest rate (in hundredths)	1.00%
Conversion price (in dollars per share) | $ / shares	$ 1.10
Common shares, issued (in shares) | shares	3,000,000
Ownership interest (in hundredths)	5.00%
Common stock in exchange for the cancelation	$ 3,300,000
Debt Instrument, Face Amount	$ 3,300,000
Non-compete Agreement Term	1 year
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	15.00%
OncoCyte [Member] | OncoCyte Common Stock [Member]
Related Party Transaction [Line Items]
Pre-offer valuation of rights				$ 40,000,000		$ 40,000,000
Maximum purchase price of shares of pre-offer				$ 3,000,000
Number of shares that can be called by warrants (in shares) | shares				3,000,000		3,000,000
Warrants exercise price (in dollars per share) | $ / shares				$ 0.01		$ 0.01