Stock Option Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2010		Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation costs	$ 3,186,859
Weighted average recognition period	5 years 11 months 19 days
Weighted-average estimated fair value of stock options granted (in dollars per share)	$ 4.13		$ 4.89
Weighted-average assumptions [Abstract]
Expected life (in years)	6 years 4 months 6 days		6 years 5 months 16 days
Risk-free interest rates (in hundredths)	1.06%		1.85%
Volatility (in hundredths)	98.88%		106.49%
Dividend yield (in hundredths)	0.00%		0.00%
Number of Options Outstanding [Rollforward]
Exercised (in shares)				125,000		125,000
$0.50 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 0.50
Number Outstanding (in shares)	1,970,400
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	1 year 9 months 7 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0.50
Number Exercisable (in shares)	1,970,400
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.50
2.30-8.58 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 2.30
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 8.58
Number Outstanding (in shares)	1,710,901
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	4 years 22 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.43
Number Exercisable (in shares)	1,004,007
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.36
$0.50-$8.58 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 0.50
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 8.58
Number Outstanding (in shares)	3,681,301
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	2 years 10 months 2 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 2.32
Number Exercisable (in shares)	2,974,407
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 1.80
0.003-$0.10 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 0.003
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 0.10
Number Outstanding (in shares)	5,216,226
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	6 years 11 months 12 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0.37
Number Exercisable (in shares)	2,790,371
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.34
1.00-1.75 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 1.00
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 1.75
Number Outstanding (in shares)	1,042,347
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	6 years 4 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 1.37
Number Exercisable (in shares)	212,250
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 1.01
2.05 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 2.05
Number Outstanding (in shares)	1,550,000
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	7 years 5 months 5 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 2.05
Number Exercisable (in shares)	681,250
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 2.05
27.00-42.02 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 27.00
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 42.02
Number Outstanding (in shares)	7,840
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	7 years 9 months 18 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 37.35
Number Exercisable (in shares)	7,840
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 37.35
0.003-$42.02 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 0.003
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 42.02
Number Outstanding (in shares)	7,816,413
Options Outstanding, Weighted Avg. Remaining Contractual Life (in years)	6 years 11 months 1 day
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0.87
Number Exercisable (in shares)	3,691,711
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.77
1992 Plan and 2002 Plan [Member]
Options Available for Grant [Rollforward]
Beginning of the period (in shares)	1,303,193		1,842,168	2,087,168
Granted (in shares)			(560,443)	(245,000)
Exercised (in shares)	0		0	0	[1]
Forfeited/expired (in shares)	0		21,468
End of the period (in shares)	3,745,000		1,303,193	1,842,168
Added by 2012 Plan (in shares)	4,000,000	[2]
Reduce options ungranted under 2002 Plan (in shares)	(1,023,193)	[3]
Number of Options Outstanding [Rollforward]
Outstanding, beginning of the period (in shares)	3,408,905		3,320,590	3,477,000
Granted (in shares)	250,000		560,443	245,000
Exercised (in shares)	(98,541)		(450,660)	(401,410)	[1]
Forfeited/expired (in shares)	(164,063)		(21,468)
Added by 2012 Plan (in shares)	0	[2]
Reduce options ungranted under 2002 Plan (in shares)	0	[3]
Outstanding, end of the period (in shares)	3,681,301		3,408,905	3,320,590
Weighted Average Exercise Price [Rollforward]
Outstanding, beginning of the period (in dollars per share)	$ 2.18		$ 1.13	1.13
Granted (in dollars per share)			$ 4.89	6.75
Exercised (in dollars per share)	$ 2.91		$ 0.50	1.56	[1]
Forfeited/expired (in dollars per share)	$ 5.60		$ 5.60
Added by 2012 Plan (in dollars per share)	$ 0	[2]
Reduce options ungranted under 2002 Plan (in dollars per share)	$ 0	[3]
Outstanding end of the period (in dollars per share)	$ 1.96		$ 2.18	1.13
2002 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance (in shares)	4,000,000
OncoCyte, OrthoCyte and ReCyte Therapeutics stock option plans [Member]
Additional Information regarding options outstanding [Abstract]
Authorize number of shares under stock option plan (in shares)	4,000,000
BioTime Asia stock option plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options to purchase for employees (in shares)	3,426,301
Additional Information regarding options outstanding [Abstract]
Authorize number of shares under stock option plan (in shares)	14,100
Cell Cure Neurosciences' option plan [Member]
Additional Information regarding options outstanding [Abstract]
Authorize number of shares under stock option plan (in shares)	1,600
Granted under 2002 Plan [Member]
Options Available for Grant [Rollforward]
Granted (in shares)	(280,000)
Number of Options Outstanding [Rollforward]
Granted (in shares)	280,000
Weighted Average Exercise Price [Rollforward]
Granted (in dollars per share)	$ 4.75
Granted under 2012 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options to purchase for employees (in shares)	4,000,000
Options Available for Grant [Rollforward]
Granted (in shares)	(255,000)
Number of Options Outstanding [Rollforward]
Granted (in shares)	255,000
Weighted Average Exercise Price [Rollforward]
Granted (in dollars per share)	$ 3.45
Lifemap Stock Option Plan [Member]
Additional Information regarding options outstanding [Abstract]
Authorize number of shares under stock option plan (in shares)			8,000,000

[1] This table excludes 250,000 options which were granted in 2008 outside the 1992 Plan and 2002 Plan, of which 125,000 were exercised in 2009 and the remaining 125,000 were exercised in 2010.

[2] During December 2012, the 2012 Equity Incentive Plan was approved by the BioTime Board of Directors making 4,000,000 common shares available for the grant of options. This plan has not yet been approved by the shareholders.

[3] During September 2012, the 2002 Plan expired.