Selected Quarterly Financial Information (UNAUDITED) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Selected Quarterly Financial Information [Abstract]
Revenues	$ 1,065,547	$ 833,817	$ 949,746	$ 631,946	$ 1,631,526	$ 1,143,054	$ 755,553	$ 824,629	$ 3,915,327	$ 4,434,159	$ 3,708,018
Operating expenses	8,124,795	6,780,375	7,029,077	6,547,486	7,078,711	5,375,419	5,736,547	4,850,516	28,481,733	23,041,193	13,532,433
Loss from operations	(7,059,248)	(5,946,558)	(6,079,331)	(5,915,540)	(5,447,185)	(4,232,365)	(4,980,994)	(4,027,887)	(25,000,677)	(18,686,431)	(9,852,133)
Net loss attributable to BioTime, Inc.	$ (6,037,125)	$ (4,958,014)	$ (5,457,222)	$ (4,973,342)	$ (5,137,814)	$ (3,737,626)	$ (4,277,928)	$ (3,362,132)	$ (21,425,703)	$ (16,515,500)	$ (11,184,618)
Basic and diluted net loss per share (in dollars per share)	$ (0.12)	$ (0.1)	$ (0.11)	$ (0.1)	$ (0.1)	$ (0.08)	$ (0.09)	$ (0.07)	$ (0.44)	$ (0.35)	$ (0.28)