Selected Quarterly Financial Information (UNAUDITED) (Details) (USD $)	3 Months Ended												12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Selected Quarterly Financial Information [Abstract]
Revenues, net	$ 1,670,063		$ 507,384		$ 1,035,514		$ 431,724		$ 1,065,547	$ 833,817	$ 949,746	$ 631,946	$ 4,434,336	$ 3,915,327	$ 4,434,159
Acquired in-process research and development	17,458,766	[1]	0	[1]	0	[1]	0	[1]					17,458,766	0	0
Operating expenses	13,504,740		10,709,337		9,151,965		8,811,633		8,124,795	6,780,375	7,029,077	6,547,486	59,626,863	28,481,733	23,041,193
Loss from operations	(29,293,443)		(10,201,953)		(8,116,451)		(8,379,909)		(7,059,248)	(5,946,558)	(6,079,331)	(5,915,540)	(55,985,186)	(25,000,677)	(18,686,431)
Net loss attributable to BioTime, Inc.	$ (19,612,314)	[2]	$ (9,003,168)	[2]	$ (7,549,765)	[2]	$ (7,719,263)	[2]	$ (6,037,125)	$ (4,958,014)	$ (5,457,222)	$ (4,973,342)	$ (43,882,835)	$ (21,425,703)	$ (16,515,500)
Basic and diluted net loss per share (in dollars per share)	$ (0.35)		$ (0.16)		$ (0.14)		$ (0.15)		$ (0.12)	$ (0.10)	$ (0.11)	$ (0.10)	$ (0.81)	$ (0.44)	$ (0.35)

[1] Includes IPR&D expenses related to intangible assets acquired by Asterias from Geron under the Asset Contribution. IPR&D represents the value of incomplete research and development projects which Asterias intends to continue. See Notes 2 and 15.

[2] Net of $3,280,695 income tax benefits in fourth quarter.