Stock Option Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation costs	$ 8,388,639
Weighted average recognition period	6 years 11 months 5 days
Weighted-average estimated fair value of stock options granted (in dollars per share)	$ 3.43	$ 4.13
Stock-based compensation expense	4,455,420	3,044,774	1,843,962
Weighted-average assumptions [Abstract]
Expected life (in years)	6 years 8 months 1 day	6 years 8 months 5 days
Risk-free interest rates (in hundredths)	2.19%	1.51%
Volatility (in hundredths)	83.20%	95.22%
Dividend yield (in hundredths)	0.00%	0.00%
Consultant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 173,100
2.52-8.58 [Member]
Additional Information regarding options outstanding [Abstract]
Number Outstanding (in shares)	3,974,326
Options Outstanding, Weighted Avg. Remaining Contractual Life	5 years 6 months 25 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.04
Number Exercisable (in shares)	1,716,099
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.48
2.52-8.58 [Member] | Minimum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 2.52
2.52-8.58 [Member] | Maximum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 8.58
$2.52-$8.58 [Member]
Additional Information regarding options outstanding [Abstract]
Number Outstanding (in shares)	3,974,326
Options Outstanding, Weighted Avg. Remaining Contractual Life	5 years 6 months 25 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.04
Number Exercisable (in shares)	1,716,099
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.48
$2.52-$8.58 [Member] | Minimum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 2.52
$2.52-$8.58 [Member] | Maximum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 8.58
0.003-$0.75 [Member]
Additional Information regarding options outstanding [Abstract]
Number Outstanding (in shares)	5,256,226
Options Outstanding, Weighted Avg. Remaining Contractual Life	4 years 11 months 16 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0.36
Number Exercisable (in shares)	5,091,506
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.37
0.003-$0.75 [Member] | Minimum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 0.003
0.003-$0.75 [Member] | Maximum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 0.75
1.00-1.75 [Member]
Additional Information regarding options outstanding [Abstract]
Number Outstanding (in shares)	1,986,772
Options Outstanding, Weighted Avg. Remaining Contractual Life	4 years 10 months 13 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 1.58
Number Exercisable (in shares)	1,157,886
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 1.50
1.00-1.75 [Member] | Minimum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 1.00
1.00-1.75 [Member] | Maximum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 1.75
2.05-2.34 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 2.05
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 2.34
Number Outstanding (in shares)	4,361,666
Options Outstanding, Weighted Avg. Remaining Contractual Life	5 years 6 months 11 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 2.26
Number Exercisable (in shares)	2,066,146
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 2.18
3.88-6.25 [Member]
Additional Information regarding options outstanding [Abstract]
Number Outstanding (in shares)	75,000
Options Outstanding, Weighted Avg. Remaining Contractual Life	0 years 1 month 13 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 0.105
Number Exercisable (in shares)	2,708
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.01
3.88-6.25 [Member] | Minimum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 3.88
3.88-6.25 [Member] | Maximum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 6.25
27.00-42.02 [Member]
Additional Information regarding options outstanding [Abstract]
Number Outstanding (in shares)	7,840
Options Outstanding, Weighted Avg. Remaining Contractual Life	5 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
27.00-42.02 [Member] | Minimum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 27.00
27.00-42.02 [Member] | Maximum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 42.02
500.00 [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 500.00
Number Outstanding (in shares)	13,167
Options Outstanding, Weighted Avg. Remaining Contractual Life	0 years 0 months 14 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.31
Number Exercisable (in shares)	1,993
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.86
0.003-$500.00 [Member]
Additional Information regarding options outstanding [Abstract]
Number Outstanding (in shares)	11,700,671
Options Outstanding, Weighted Avg. Remaining Contractual Life	5 years 2 months 1 day
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 1.90
Number Exercisable (in shares)	8,328,079
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 1.13
0.003-$500.00 [Member] | Minimum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Lower Range Limit (in dollars per share)	$ 0.003
0.003-$500.00 [Member] | Maximum [Member]
Additional Information regarding options outstanding [Abstract]
Range of Exercise Prices, Upper Range Limit (in dollars per share)	$ 500.00
2002 Plan and 2012 Plan [Member]
Options Available for Grant [Rollforward]
Beginning of the period (in shares)	2,315,000	3,745,000
Granted (in shares)	(2,170,000)
Exercised (in shares)	0	0
End of the period (in shares)	667,918	2,315,000
Number of Options Outstanding [Rollforward]
Outstanding, beginning of the period (in shares)	4,567,135	3,681,301
Granted (in shares)	2,170,000
Exercised (in shares)	(2,060,400)	(20,000)
Outstanding, end of the period (in shares)	3,974,326	4,567,135
Weighted Average Exercise Price [Rollforward]
Outstanding, beginning of the period (in dollars per share)	$ 2.71	$ 1.96
Granted (in dollars per share)	$ 3.54
Exercised (in dollars per share)	$ 0.58	$ 2.30
Outstanding end of the period (in dollars per share)	$ 4.04	$ 2.71
2002 Plan [Member]
Options Available for Grant [Rollforward]
Forfeited/expired (in shares)	0	0
Number of Options Outstanding [Rollforward]
Forfeited/expired (in shares)	(179,491)	(524,166)
Weighted Average Exercise Price [Rollforward]
Forfeited/expired (in dollars per share)	$ 4.32	$ 4.01
2012 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for future issuance (in shares)			4,000,000
Period when options may not be granted or exercised			10 years
Options Available for Grant [Rollforward]
Granted (in shares)		(1,585,000)
Forfeited/expired (in shares)	522,918	155,000
Number of Options Outstanding [Rollforward]
Granted (in shares)		1,585,000
Forfeited/expired (in shares)	(522,918)	(155,000)
Weighted Average Exercise Price [Rollforward]
Granted (in dollars per share)		$ 4.13
Forfeited/expired (in dollars per share)	$ 3.72	$ 4.18
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)		4,500,000
Additional Information regarding options outstanding [Abstract]
Authorize number of shares under stock option plan (in shares)	1,600
Cell Cure Neurosciences' option plan [Member]
Additional Information regarding options outstanding [Abstract]
Authorize number of shares under stock option plan (in shares)	14,100
Lifemap Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reverse stock split			1 for 4 reverse stock split
Options Available for Grant [Rollforward]
End of the period (in shares)			1,842,168
Additional Information regarding options outstanding [Abstract]
Authorize number of shares under stock option plan (in shares)		18,667		8,000,000