Lineage Cell Therapeutics (LCTX) 10-K 11 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Mar. 09, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	BIOTIME INC
Entity Central Index Key	876343
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$120,375,039
Entity Common Stock, Shares Outstanding		83,154,787
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
CURRENT ASSETS
Cash and cash equivalents	$29,486,909	$5,495,478
Trade accounts and grants receivable, net	1,041,856	1,115,209
Inventory	266,022	178,694
Landlord receivable	377,981	0
Prepaid expenses and other current assets	1,231,789	1,160,589
Total current assets	32,404,557	7,949,970
Equipment, net	2,857,846	2,997,733
Deferred license and consulting fees	336,833	444,833
Deposits	443,289	129,129
Other long-term assets	9,985	0
Intangible assets, net	38,848,396	46,208,085
TOTAL ASSETS	74,900,906	57,729,750
CURRENT LIABILITIES
Accounts payable and accrued liabilities	6,803,173	6,722,624
Capital lease liability, current portion	57,500	0
Related party convertible debt, net of discount	60,237	0
Deferred license and subscription revenue, current portion	208,357	235,276
Total current liabilities	7,129,267	6,957,900
LONG-TERM LIABILITIES
Deferred tax liability net	4,514,362	8,277,548
Deferred rent liabilities	97,280	35,997
Lease liabilities	377,981	0
Capital lease, net of current portion	31,290	0
Other long term liabilities	27,961	195,984
Total long-term liabilities	5,048,874	8,509,529
Commitments and contingencies
SHAREHOLDERS' EQUITY
Preferred shares, no par value, authorized 2,000,000 shares as of December 31, 2014 and 2013; 70,000 and none issued and outstanding as of December 31, 2014 and 2013, respectively	3,500,000	0
Common shares, no par value, authorized 125,000,000 shares as of December 31, 2014 and 2013; 83,121,698 issued and 78,227,756 outstanding as of December 31, 2014 and 67,412,139 issued and 56,714,424 outstanding as of December 31, 2013	234,842,998	203,456,401
Contributed capital	7,145	93,972
Accumulated other comprehensive income	185,835	62,899
Accumulated deficit	-182,190,207	-145,778,547
Treasury stock at cost: 4,893,942 and 10,697,715 shares at December 31, 2014 and 2013, respectively	-19,889,788	-43,033,957
BioTime shareholders' equity	36,455,983	14,800,768
Non-controlling interest	26,266,782	27,461,553
Total shareholders' equity	62,722,765	42,262,321
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$74,900,906	$57,729,750

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
SHAREHOLDERS' EQUITY
Preferred Shares, par value (in dollars per share)	$0	$0
Preferred Shares, authorized (in shares)	2,000,000	2,000,000
Preferred Shares, issued (in shares)	70,000	0
Preferred shares outstanding (in shares)	70,000	0
Common shares, par value (in dollars per share)	$0	$0
Common shares, authorized (in shares)	125,000,000	125,000,000
Common shares, issued (in shares)	83,121,698	67,412,139
Common shares, outstanding (in shares)	78,227,756	56,714,424
Treasury stock (in shares)	4,893,942	10,697,715

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
REVENUES:
License fees	$1,172,860	$2,218,174	$899,998
Royalties from product sales	397,751	366,775	541,681
Grant income	3,296,832	1,573,329	2,222,458
Sale of research products and services	375,761	276,058	251,190
Total revenues	5,243,204	4,434,336	3,915,327
Cost of sales	-837,052	-792,659	-434,271
Gross Profit	4,406,152	3,641,677	3,481,056
EXPENSES:
Research and development	-37,532,624	-26,609,423	-18,116,688
Acquired in-process research and development	0	-17,458,766	0
General and administrative	-17,556,102	-15,558,674	-10,365,045
Total operating expenses	-55,088,726	-59,626,863	-28,481,733
Loss from operations	-50,682,574	-55,985,186	-25,000,677
OTHER EXPENSES:
Interest (expense)/income, net	-88,496	-578	19,383
(Loss)/gain on sale or write off of fixed assets	-8,926	5,120	-6,856
Other expense, net	-374,715	-209,177	-317,710
Total other expenses, net	-472,137	-204,635	-305,183
LOSS BEFORE INCOME TAX BENEFITS	-51,154,711	-56,189,821	-25,305,860
Deferred income tax benefit	7,375,611	3,280,695	0
NET LOSS	-43,779,100	-52,909,126	-25,305,860
Net loss attributable to non-controlling interest	7,367,440	9,026,291	3,880,157
COMPREHENSIVE LOSS ATTRIBUTABLE TO COMMON SHAREHOLDERS	-36,411,660	-43,882,835	-21,425,703
Dividends on preferred shares	-86,827	0	0
Net loss attributable to BioTime, Inc. common shareholders	($36,498,487)	($43,882,835)	($21,425,703)
BASIC AND DILUTED NET LOSS PER COMMON SHARE (in dollars per share)	($0.55)	($0.81)	($0.44)
WEIGHTED AVERAGE NUMBER OF COMMON STOCK OUTSTANDING: BASIC AND DILUTED (in shares)	66,466,714	54,226,219	49,213,687

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS
NET LOSS	($43,779,100)	($52,909,126)	($25,305,860)
Other comprehensive income/(loss), net of tax:
Change in foreign currency translation and other comprehensive income/(loss) from equity investments	124,949	119,469	63,179
Available for sale investments:
Change in other unrealized gain/(loss), net of taxes	-2,013	3,000	0
COMPREHENSIVE LOSS	-43,656,164	-52,786,657	-25,242,681
Less: Comprehensive loss attributable to noncontrolling interest	-7,367,440	-9,026,291	-3,880,157
Dividends on preferred shares	-86,827	0	0
COMPREHENSIVE LOSS ATTRIBUTABLE TO BIOTIME, INC. COMMON SHAREHOLDERS BEFORE PREFERRED STOCK DIVIDEND	-36,288,724	-43,760,366	-21,362,524
COMPREHENSIVE LOSS ATTRIBUTABLE TO BIOTIME, INC. COMMON SHAREHOLDERS	($36,375,551)	($43,760,366)	($21,362,524)

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (USD $)	Preferred Stock [Member]	Common Shares [Member]	Treasury Shares [Member]	Contributed Capital [Member]	Accumulated Deficit [Member]	Noncontrolling Interest [Member]	Accumulated Other Comprehensive Income [Member]	Total
BALANCE at Dec. 31, 2011	$0	$115,144,787	($6,000,000)	$93,972	($80,470,009)	$12,812,180	($122,749)	$41,458,181
BALANCE (in shares) at Dec. 31, 2011	0	50,321,962	-1,286,174
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common shares issued as part of merger with XenneX		1,802,684						1,802,684
Common shares issued as part of merger with XenneX (in shares)		448,429
Common shares retired as payment for exercise of options								0
Sale of common shares, net of fees paid and amortized and syndication costs		1,002,220						1,002,220
Sale of common shares, net of fees paid and amortized and syndication costs (in shares)		314,386
Common shares issued for rent								0
Common shares issued for consulting services								0
Exercise of options		286,552						286,552
Exercise of options (in shares)		98,541
Subsidiary shares issued as part of merger with XenneX						2,501,415		2,501,415
Stock options granted for compensation		1,560,469						1,560,469
Stock options granted for compensation in subsidiaries		24,531				274,656		299,187
Outside investment in subsidiary with BioTime common shares			-2,750,003			2,750,003		0
Outside investment in subsidiary with BioTime common shares (in shares)			-592,533
Sales of treasury shares			374,606					374,606
Sales of treasury shares (in shares)			78,598
Dividends on preferred shares								0
Outside investment in subsidiaries in cash						250,000		250,000
Outside investment in subsidiaries with stock						1,740		1,740
Foreign currency translation gain							63,179	63,179
NET LOSS					-21,425,703	-3,880,157		-25,305,860
BALANCE at Dec. 31, 2012	0	119,821,243	-8,375,397	93,972	-101,895,712	14,709,837	-59,570	24,294,373
BALANCE (in shares) at Dec. 31, 2012	0	51,183,318	-1,800,109
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common shares retired as payment for exercise of options								0
Common shares issued as part of investment in subsidiary		38,485,162	-38,485,162
Common shares issued as part of investment in subsidiary (in shares)		9,808,812	-9,808,812
8,000,000 Warrants issued as part of investment in subsidiary		18,276,406						18,276,406
Sale of common shares, net of fees paid and amortized and syndication costs		22,297,209						22,297,209
Sale of common shares, net of fees paid and amortized and syndication costs (in shares)		6,284,456
Warrants issued to outside investors		1,848,730						1,848,730
Common shares issued for rent		253,758						253,758
Common shares issued for rent (in shares)		73,553
Common shares issued for consulting services		173,100						173,100
Common shares issued for consulting services (in shares)		42,000
Exercise of options		46,000						46,000
Exercise of options (in shares)		20,000
Stock options granted for compensation		2,143,596						2,143,596
Stock options granted for compensation in subsidiaries		111,197				789,981		901,178
Sales of treasury shares			3,826,602					3,826,602
Sales of treasury shares (in shares)			911,206
Dividends on preferred shares								0
Outside investment in subsidiaries in cash						5,255,502		5,255,502
Outside investment in subsidiary with assets						15,732,524		15,732,524
Foreign currency translation gain							119,469	119,469
Unrealized loss on available-for-sale securities							3,000	3,000
NET LOSS					-43,882,835	-9,026,291		-52,909,126
BALANCE at Dec. 31, 2013	0	203,456,401	-43,033,957	93,972	-145,778,547	27,461,553	62,899	42,262,321
BALANCE (in shares) at Dec. 31, 2013	0	67,412,139	-10,697,715					56,714,424
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common shares retired as payment for exercise of options		-972,700						-972,700
Common shares retired as payment for exercise of options (in shares)		-367,057
Common shares retired to pay for employee's taxes		-414,935						-414,935
Common shares retired to pay for employee's taxes (in shares)		-156,579
Deferred Tax Liability Adjustment On Treasury Stock Issued And Held By Acquiree Entity		-3,611,902						-3,611,902
Sale of common shares, net of fees paid and amortized and syndication costs		43,826,687						43,826,687
Sale of common shares, net of fees paid and amortized and syndication costs (in shares)		14,172,785
Common shares issued for rent								0
Common shares issued for consulting services								0
Exercise of options		1,192,200						1,192,200
Exercise of options (in shares)		2,060,400
Warrants exercised		50						50
Warrants exercised (in shares)		10
Stock options granted for compensation		2,408,935						2,408,935
Stock options granted for compensation in subsidiaries						1,808,118		1,808,118
Restricted stock granted for compensation						234,005		234,005
Susidiary warrants issued to outside investors as part of sale of treasury stock						3,183,891		3,183,891
Sales of treasury shares		-11,041,738	23,144,169					12,102,431
Sales of treasury shares (in shares)			5,803,773
Sale of preferred stock	3,500,000							3,500,000
Sale of preferred stock (in shares)	70,000
Dividends on preferred shares				-86,827				-86,827
Stock Issued During Period Shares Subsidiary Stock Options Exercised						7,799		7,799
Outside investment in subsidiaries in cash						938,856		938,856
Foreign currency translation gain							124,949	124,949
Unrealized loss on available-for-sale securities							-2,013	-2,013
NET LOSS					-36,411,660	7,367,440		-43,779,100
BALANCE at Dec. 31, 2014	$3,500,000	$234,842,998	($19,889,788)	$7,145	($182,190,207)	$26,266,782	$185,835	$62,722,765
BALANCE (in shares) at Dec. 31, 2014	70,000	83,121,698	-4,893,942					78,227,756

CONSOLIDATED_STATEMENTS_OF_CHA1

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical)	Dec. 31, 2013
CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY [Abstract]
Warrants issued as part of investment in subsidiary (in shares)	8,000,000

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss attributable to BioTime, Inc.	($36,411,660)	($43,882,835)	($21,425,703)
Net loss allocable to non-controlling interest	-7,367,440	-9,026,291	-3,880,157
Adjustments to reconcile net loss attributable to BioTime, Inc. to net cash used in operating activities:
Acquired in-process research and development	0	17,458,766	0
Depreciation expense	1,050,651	656,759	386,457
Amortization of intangible assets	7,359,690	3,295,716	2,446,975
Amortization of deferred consulting fees	18,993	65,118	598,465
Amortization of deferred license fees	109,500	109,500	109,500
Amortization of deferred license, royalty and subscription revenues	-579	-915,028	-211,065
Amortization of deferred grant revenues	0	0	-261,777
Amortization of prepaid rent in common stock	84,586	84,586	0
Stock-based compensation	4,455,420	3,217,875	1,843,962
Reduction in receivables from the reversal of revenues	0	0	207,425
Amortization of discount on related party convertible debt	56,320	0	0
Amortization of deferred royalty fees (expense)	15	0	0
Loss/(gain) on sale or write-off of equipment	9,321	-5,120	19,681
Bad debt expense	0	0	16,816
Deferred income tax benefit	-7,375,611	-3,280,695	0
Write-off for uncollectible receivables	-16,356	0	0
Changes in operating assets and liabilities:
Accounts receivable, net	-73,784	-180,933	36,322
Grant receivable	11,325	560,286	-416,787
Inventory	-87,328	-123,378	-4,141
Prepaid expenses and other current assets	-86,427	428,453	-228,370
Other long term assets	0	-15,000	0
Accounts payable and accrued liabilities	-469,755	2,141,893	906,339
Accrued interest on convertible debt	4,226	0	0
Other long term liabilities	-160,250	-57,824	-26,088
Deferred rent liabilities	61,283	-21,217	-9,474
Deferred revenues	-26,340	-19,244	212,102
Net cash used in operating activities	-38,854,200	-29,508,613	-19,679,518
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of equipment	-483,097	-2,277,168	-400,810
Cash acquired in connection with merger with XenneX	0	0	292,387
Construction in progress	-219,443	0	0
Payment of transaction fees to Geron	0	-978,104	0
Payment of syndication fees incurred	0	-376,250	0
Cash proceeds from sale of equipment	9,242	30,900	4,500
Security deposit paid, net	-314,506	-64,965	-764
Net cash used in investing activities	-1,007,804	-3,665,587	-104,687
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercises of stock options	219,500	46,000	286,552
Proceeds from exercises of warrants	50	0	0
Proceeds from sale of preferred shares	3,500,000	0	0
Proceeds from issuance of common shares	44,150,069	25,938,558	1,131,279
Fees paid on sale of common shares	-323,382	-818,201	-37,279
Proceeds from sale of treasury stock and subsidiary warrants	15,156,561	3,841,749	282,826
Proceeds from issuance of related party convertible debt	470,856	0	0
Repayment of capital lease obligation	-26,210	0	0
Proceeds from exercise of subsidiary stock options	7,799	0	0
Proceeds from sale of common shares of subsidiary	468,000	5,255,502	250,000
Net cash provided by financing activities	63,623,243	34,263,608	1,913,378
Effect of exchange rate changes on cash and cash equivalents	230,192	56,103	8,897
NET CHANGE IN CASH AND CASH EQUIVALENTS	23,991,431	1,145,511	-17,861,930
CASH AND CASH EQUIVALENTS:
At beginning of year	5,495,478	4,349,967	22,211,897
At end of year	29,486,909	5,495,478	4,349,967
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during year for interest	91,047	3,090	315
SUPPLEMENTAL SCHEDULE OF NONCASH FINANCING AND INVESTING ACTIVITIES :
Common shares issued to Cell Cure in exchange for Cell Cure shares	0	3,499,999	0
Common shares issued for consulting services	0	173,100	0
Common shares issued for rent	0	253,758	0
Intangible assets acquired from Geron	0	29,017,009	0
Common shares issued to Asterias upon consummation of asset contribution (Treasury shares)	0	34,985,163	0
Common shares acquired in connection with investment in LifeMap as part of Share Exchange and Contribution Agreement	0	0	2,750,003
Common shares issued as part of merger with XenneX	0	0	1,802,684
Employee options exercised with common stock	972,700	0	0
Capital expenditure funded by capital lease borrowing	115,000	0	0
Construction in progress in accounts payable and accrued expenses	186,727	0	0
Land lord receivable	-377,981	0	0
Lease liability	377,981	0	0
Warrants issued to Asterias upon consummation of asset contribution	$0	$18,276,406	$0

Organization_and_Basis_of_Pres

Organization and Basis of Presentation and Liquidity	12 Months Ended
	Dec. 31, 2014
Organization and Basis of Presentation and Liquidity [Abstract]
Organization and Basis of Presentation and Liquidity	1. Organization, Basis of Presentation and Liquidity
	General – BioTime is a biotechnology company focused on the field of regenerative medicine; specifically human embryonic stem (“hES”) cell and induced pluripotent stem (“iPS”) cell technology. Regenerative medicine refers to therapies based on stem cell technology that are designed to rebuild cell and tissue function lost due to degenerative disease or injury. hES and iPS cells provide a means of manufacturing every cell type in the human body and therefore show considerable promise for the development of a number of new therapeutic products. BioTime and its subsidiaries plan to develop stem cell products for research and therapeutic use. BioTime’s primary therapeutic products are based on its HyStem® hydrogel technology and include Renevia™ a product currently in clinical trials in Europe to facilitate cell transplantation; ReGlyde™ a product under development for tendon surgery applications, and Premvia™ for which 510(k) certification has been received for use in wound-management. Asterias Biotherapeutics, Inc. (“Asterias”) is developing pluripotent stem-cell based therapies in neurology and oncology, including AST-OPC1 neural cells in spinal cord injury, multiple sclerosis and stroke, and AST-VAC2, a pluripotent stem cell-derived cancer vaccine. OncoCyte Corporation (“OncoCyte”) is developing products and technologies to diagnose cancer. ES Cell International Pte Ltd. (“ESI”), a Singapore private limited company, has developed hES cell lines under current good manufacturing practices that have been approved by the NIH for inclusion in the Human Embryonic Stem Cell Registry, and that are being marketed by BioTime for research purposes under the ESI BIO branding program. OrthoCyte Corporation (“OrthoCyte”) is developing therapies to treat orthopedic disorders, diseases and injuries. ReCyte Therapeutics, Inc. (“ReCyte Therapeutics”) is developing therapies to treat a variety of cardiovascular and related ischemic disorders, as well as products for research using cell reprogramming technology. Cell Cure Neurosciences Ltd. (“Cell Cure Neurosciences”) is an Israel-based biotechnology company focused on developing stem cell-based therapies for retinal and neurological disorders, including the development of retinal pigment epithelial cells for the treatment of macular degeneration, and treatments for multiple sclerosis. LifeMap Sciences, Inc. (“LifeMap Sciences”) markets, sells and distributes GeneCards®, the leading human gene database and an integrated database suite that includes GeneCards®, the LifeMap Discovery® database of embryonic development, stem cell research and regenerative medicine, and MalaCards™, the human disease database, and the analysis tools VarElect™, a powerful, yet easy-to-use application for prioritizing gene variants resulting from next generation sequencing experiments, and GeneAnalytics™, a novel gene set analysis tool. LifeMap Sciences’ subsidiary LifeMap Solutions, Inc. (“LifeMap Solutions”) is developing mobile health software products.
	BioTime is focusing a portion of its efforts in the field of regenerative medicine on the development and sale of advanced human stem cell products and technologies that can be used by researchers at universities and other institutions, at companies in the bioscience and biopharmaceutical industries, and at other companies that provide research products to companies in those industries. Products for the research market generally can be sold without regulatory (United States Food and Drug Administration (“FDA”)) approval, and are therefore relatively near-term business opportunities when compared to therapeutic products.
	BioTime previously developed blood plasma volume expanders and related technology for use in surgery, emergency trauma treatment and other applications. BioTime’s operating revenues are now derived primarily from research grants, from licensing fees and advertising from the marketing of the LifeMap Sciences database products, and from the sale of products for research.
	The consolidated balance sheets as of December 31, 2014 and 2013, the consolidated statements of operations for the years ended December 31, 2014, 2013, and 2012, consolidated statements of comprehensive loss for the years ended December 31, 2014, 2013, and 2012, the consolidated statements of changes in shareholders' equity for the years ended December 31, 2014, 2013, and 2012, and the consolidated statements of cash flows for the years ended December 31, 2014, 2013, and 2012 have been prepared by BioTime’s management in accordance with instructions on Form 10-K.
	Use of estimates - The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the U.S. ("GAAP") requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Principles of consolidation – BioTime’s consolidated financial statements include the accounts of its subsidiaries. The following table reflects BioTime’s ownership, directly or through one or more subsidiaries, of the outstanding shares of its subsidiaries as of December 31, 2014.
			BioTime
	Subsidiary	Field of Business	Ownership	Country
	Asterias Biotherapeutics, Inc.	Research, development and commercialization of human therapeutic products from stem cells, focused initially in the fields of neurology and oncology	70.6%(1)	USA
	BioTime Asia, Limited	Stem cell products for research	81%	Hong Kong
	Cell Cure Neurosciences Ltd.	Age-related macular degeneration	62.5%(2)	Israel
		Multiple sclerosis
		Parkinson’s disease
	ES Cell International Pte Ltd	Stem cell products for research, including clinical grade cell lines produced under cGMP	100%	Singapore
	LifeMap Sciences, Inc.	Biomedical, gene, disease, and stem cell databases and tools	74.50%	USA
	LifeMap Sciences, Ltd.	Biomedical, gene, disease, and stem cell databases and tools	-3	Israel
	LifeMap Solutions, Inc.	Mobile health software	-3	USA
	OncoCyte Corporation	Cancer diagnostics	75.30%	USA
	OrthoCyte Corporation	Orthopedic diseases, including chronic back pain and osteoarthritis	100%(4)	USA
	ReCyte Therapeutics, Inc.	Vascular disorders, including cardiovascular-related diseases, ischemic conditions, vascular injuries	94.80%	USA
		Stem cell-derived endothelial and cardiovascular related progenitor cells that have applications in research, drug testing, and therapeutics
		-1	During February 2015, Asterias sold 1,410,255 shares of its Series A Common Stock to investors, which reduced BioTime’s percentage ownership of Asterias to 67.5%.
		-2	Includes shares owned by BioTime, Asterias, and ESI.
		-3	LifeMap Sciences, Ltd. and LifeMap Solutions, Inc. are wholly-owned subsidiaries of LifeMap Sciences, Inc.
		-4	Includes shares owned by BioTime and Asterias.
	All material intercompany accounts and transactions have been eliminated in consolidation. The consolidated financial statements are presented in accordance with GAAP and with the accounting and reporting requirements of SEC Regulation S-X. As of December 31, 2014, BioTime consolidated Asterias, ReCyte Therapeutics, OncoCyte, OrthoCyte, ESI, Cell Cure Neurosciences, BioTime Asia, Limited (“BioTime Asia”), LifeMap Sciences, LifeMap Sciences, Ltd., and LifeMap Solutions as BioTime has the ability to control their operating and financial decisions and policies through its ownership, and the non-controlling interest is reflected as a separate element of shareholders' equity on BioTime’s consolidated balance sheets.
	Liquidity – Since inception, BioTime has incurred significant net losses and has funded its operations primarily through the issuance of equity securities, payments from research grants, royalties from product sales and sales of research products and services. At December 31, 2014, BioTime had an accumulated deficit of $182,190,207, working capital of $25,275,290 and shareholders’ equity of $62,722,765. BioTime has evaluated its projected cash flows for it and its subsidiaries and believes that its cash and cash equivalents of $29,486,909 as of December 31, 2014, will be sufficient to fund its operations at least through 2015. However, clinical trials being conducted by BioTime’s subsidiaries Asterias and Cell Cure Neurosciences will be funded in part with funds from grants and not from cash on hand. If Asterias or Cell Cure Neurosciences were to lose its grant funding it may be required to delay, postpone, or cancel its clinical trials or limit the number of clinical trial sites, or otherwise reduce or curtail its operations unless it is able to obtain from another source of adequate financing that could be used for its clinical trial.
	Certain significant risks and uncertainties – The operations of BioTime and its subsidiaries are subject to a number of factors that can affect their operating results and financial condition. Such factors include but are not limited to, the following: the results of clinical trials of their respective therapeutic product and medical device candidates; their ability to obtain FDA and foreign regulatory approval to market their respective therapeutic and medical device product candidates; their ability to develop new stem cell research products and technologies; competition from products manufactured and sold or being developed by other companies; the price and demand for their products; their ability to obtain additional financing and the terms of any such financing that may be obtained; their ability to negotiate favorable licensing or other manufacturing and marketing agreements for its products; the availability of ingredients used in their products; and the availability of reimbursement for the cost of their therapeutic products and medical devices (and related treatment) from government health administration authorities, private health coverage insurers, and other organizations.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies
	Revenue recognition – BioTime complies with ASC 605-10 and recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collectability is reasonably assured. Grant income and the sale of research products and services are recognized as revenue when earned. Revenues from the sale of research products and services are primarily derived from the sale of hydrogels and stem cell products. Royalty revenues consist of product royalty payments. License fee revenues consist primarily of subscription and advertising revenue from LifeMap Sciences’ online databases which are recognized based upon respective subscription or advertising periods. Other license fees under certain license agreements were recognized during prior periods when earned and reasonably estimable. Royalties earned on product sales are recognized as revenue in the quarter in which the royalty reports are received from the licensee, rather than the quarter in which the sales took place. When BioTime is entitled to receive up-front nonrefundable licensing or similar fees pursuant to agreements under which BioTime has no continuing performance obligations, the fees are recognized as revenues when collection is reasonably assured. When BioTime receives up-front nonrefundable licensing or similar fees pursuant to agreements under which BioTime does have continuing performance obligations, the fees are deferred and amortized ratably over the performance period. If the performance period cannot be reasonably estimated, BioTime amortizes nonrefundable fees over the life of the contract until such time that the performance period can be more reasonably estimated. Milestone payments, if any, related to scientific or technical achievements are recognized in income when the milestone is accomplished if (a) substantive effort was required to achieve the milestone, (b) the amount of the milestone payment appears reasonably commensurate with the effort expended, and (c) collection of the payment is reasonably assured.
	Cash and cash equivalents – BioTime considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.
	Trade accounts and grants receivable, net – Net trade receivables amounted to approximately $549,300 and $575,900 and grants receivable amounted to approximately $492,600 and $539,300 as of December 31, 2014 and December 31, 2013, respectively. Net trade receivables include allowance for doubtful accounts of approximately $100,500 and $116,800 as of December 31, 2014 and December 31, 2013, respectively for those amounts deemed uncollectible by BioTime. BioTime evaluates the collectability of its receivables based on a variety of factors, including the length of time receivables are past due and significant one-time events and historical experience. An additional reserve for individual accounts will be recorded if BioTime becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy filings or deterioration in the customer’s operating results or financial position. If circumstances related to customers change, estimates of the recoverability of receivables would be further adjusted.
	Concentrations of credit risk – Financial instruments that potentially subject BioTime to significant concentrations of credit risk consist primarily of cash and cash equivalents. BioTime limits the amount of credit exposure of cash balances by maintaining its accounts in high credit quality financial institutions. Cash equivalent deposits with financial institutions may occasionally exceed the limits of insurance on bank deposits; however, BioTime has not experienced any losses on such accounts.
	Inventory – Inventories are stated at the lower of cost or market. Cost, which includes amounts related to materials, labor, and overhead, is determined in a manner which approximates the first-in, first-out (“FIFO”) method.
	Equipment, net – Equipment is stated at cost. Equipment is being depreciated using the straight-line method over a period of 36 to 120 months. See Note 4.
	Intangible assets, net – Intangible assets with finite useful lives are amortized over their estimated useful lives and intangible assets with indefinite lives are not amortized but rather are tested at least annually for impairment. Acquired in-process research and development intangible assets are accounted for depending on whether they were acquired as part of an acquisition of a business, or as assets that do not constitute a business. When acquired in conjunction with the acquisition of a business, these assets are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts and are capitalized as an asset. If and when development is complete, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. However, when acquired in conjunction with an acquisition of assets that do not constitute a business (such as the acquisition of assets by Asterias from Geron Corporation), in accordance with the accounting rules in ASC 805-50, such intangible assets related to in-process research and development (“IPR&D”) are expensed upon acquisition. See Note 14.
	Treasury stock – BioTime accounts for BioTime common shares issued to subsidiaries for future potential working capital needs as treasury stock on the consolidated balance sheet. BioTime has the intent and ability to register any unregistered shares to support the marketability of the shares.
	Warrants to purchase common stock – BioTime generally accounts for warrants issued in connection with equity financings as a component of equity. None of the warrants issued by BioTime as of December 31, 2014 include a conditional obligation to issue a variable number of shares; nor was there a deemed possibility that BioTime may need to settle the warrants in cash.
	Cost of sales – BioTime accounts for the cost of research products acquired for sale and any royalties paid as a result of any revenues in accordance with the terms of the respective licensing agreements as cost of sales on the consolidated statement of operations and comprehensive loss.
	Patent costs – Costs associated with obtaining patents on products or technology developed are expensed as general and administrative expenses when incurred.
	Reclassification – Certain prior year amounts have been reclassified to conform to the current year presentation. Trade and grant receivables are now reported separately from prepaid expenses and other current assets.
	Research and development – Research and development costs are expensed when incurred, and consist principally of salaries, payroll taxes, consulting fees, research and laboratory fees, rent of research facilities, and license fees paid to third parties to acquire patents or licenses to use patents and other technology.
	Foreign currency translation gain and comprehensive loss – In countries in which BioTime operates, where the functional currency is other than the U.S. dollar, assets and liabilities are translated using published exchange rates in effect at the consolidated balance sheet date. Revenues and expenses and cash flows are translated using an approximate weighted average exchange rate for the period. Resulting translation adjustments are recorded as a component of accumulated other comprehensive loss on the consolidated balance sheet. For the fiscal years ended December 31, 2014 and 2013, comprehensive loss includes gain of $122,936 and $122,469, respectively which is largely from foreign currency translation. For the fiscal years ended December 31, 2014 and 2013, foreign currency transaction loss amounted to $338,076 and $133,479, respectively.
	Income taxes – BioTime accounts for income taxes in accordance with GAAP requirements, which prescribe the use of the asset and liability method, whereby deferred tax asset or liability account balances are calculated at the balance sheet date using current tax laws and rates in effect. Valuation allowances are established when necessary to reduce deferred tax assets when it is more likely than not that a portion or all of the deferred tax assets will not be realized. The FASB guidance also prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more-likely-than-not sustainable upon examination by taxing authorities. Beginning October 1, 2013, Asterias began filing separate U.S. federal income tax returns but effectively BioTime combined Asterias’ tax provision with BioTime’s. For California, Asterias’ activity for 2013 and 2014 will be included in BioTime’s combined tax return. BioTime recognizes accrued interest and penalties related to unrecognized tax benefits as income tax expense, however, no amounts were accrued for the payment of interest and penalties as of December 31, 2014 and December 31, 2013.  BioTime files a U.S. federal income tax return as well as various state and foreign income tax returns. In general, BioTime is no longer subject to tax examination by major taxing authorities for years before 2010.  Although the statute is closed for purposes of assessing additional income and tax in these years, the taxing authorities may still make adjustments to the net operating loss and credti carryforwards used in open years.  Therefore the statute should be considered open as it relates to the net operating loss and credit carryforwards.  Any potential examinations may include questioning the timing and amount of deductions, the nexus of income among various tax jurisdictions and compliance with U.S. federal, state and local and foreign tax laws. Management does not expect that the total amount of unrecognized tax benefits will materially change over the next year.
	A deferred income tax benefit of approximately $7,376,000 was recorded for the year ended December 31, 2014, of which approximately $5,155,000 of the benefit was related to federal and $2,221,000 was related to state taxes. A deferred income tax benefit of approximately $3,280,000 was recorded for the year ended December 31, 2013, of which approximately $2,800,000 was related to federal and $480,000 was related to state taxes. As disclosed in Note 14, Asterias established deferred tax liabilities primarily related to its acquisition of certain intellectual property. It is more likely than not that the Asterias deferred tax assets are fully realizable since these income tax benefits are expected to be available to offset such Asterias deferred tax liabilities.
	In June 2014, Asterias' sale of BioTime shares resulted in a taxable gain of approximately $10.3 million and a tax payable of $3.6 million. Asterias received the BioTime shares from BioTime as part of their consideration under the Asset Contribution Agreement, a tax free transaction. This payable, however, is expected to be fully offset by available net operating losses thus, resulting in no cash income taxes due from that sale.  This transaction was treated as a deemed distribution by Asterias and recorded against equity.
	Stock-based compensation – BioTime follows accounting standards governing share-based payments, which require the measurement and recognition of compensation expense for all share-based payment awards made to directors and employees, including employee stock options, based on estimated fair values. Consistent with FASB guidelines, BioTime utilizes the Black-Scholes Merton option pricing model for valuing share-based payment awards. BioTime's determination of fair value of share-based payment awards on the date of grant using that option-pricing model is affected by BioTime's stock price as well as by assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, BioTime's expected stock price volatility over the term of the awards, and actual and projected employee stock option exercise behaviors. The expected term of options granted is derived from historical data on employee exercises and post-vesting employment termination behavior. The risk-free rate is based on the U.S. Treasury rates in effect during the corresponding period of grant. Although the fair value of employee stock options is determined in accordance with recent FASB guidance, changes in the subjective assumptions can materially affect the estimated value.
	Impairment of long-lived assets – BioTime’s long-lived assets, including intangible assets, are reviewed annually for impairment and whenever events or changes in circumstances indicate that the carrying amount of an asset may not be fully recoverable. If an impairment indicator is present, BioTime will evaluate recoverability by a comparison of the carrying amount of the assets to future undiscounted net cash flows expected to be generated by the assets. If the assets are impaired, the impairment recognized is measured by the amount by which the carrying amount exceeds the estimated fair value of the assets.
	Deferred license and consulting fees – Deferred license and consulting fees consist of the value of warrants issued to third parties for services, and deferred license fees paid to acquire rights to use the proprietary technologies of third parties. The value of the warrants is being amortized over the period the services are being provided, and the license fees are being amortized over the estimated useful lives of the licensed technologies or licensed research products. BioTime is applying a 10 year estimated useful life to the technologies and products that it is currently licensing. The estimation of the useful life any technology or product involves a significant degree of inherent uncertainty, since the outcome of research and development or the commercial life of a new product cannot be known with certainty at the time that the right to use the technology or product is acquired. BioTime will review the continued appropriateness of the 10 year estimated useful life for impairments that might occur earlier than the original expected useful lives. See Note 6.
	Loss per share – Basic net loss per share attributable to common shareholders is computed by dividing net loss attributable to the common shareholders of BioTime by the weighted-average number of common stock outstanding for the period. Diluted net loss per share reflects the weighted-average number of common stock outstanding plus the potential effect of dilutive securities or contracts which are convertible to common shares, such as options and warrants (using the treasury stock method) and shares issuable in future periods. Diluted net loss per share for years ended December 31, 2014, 2013, and 2012 excludes any effect from 4,893,942 treasury shares, 3,974,326 options and 9,194,679 warrants, 10,697,715 treasury shares, 4,567,135 options and 9,751,615 warrants, and 1,800,109 treasury shares, 3,681,301 options and 556,613 warrants, respectively because their inclusion would be antidilutive.
	Fair value of financial instruments – The fair value of BioTime’s assets and liabilities, which qualify as financial instruments under FASB guidance regarding disclosures about fair value of financial instruments, approximate the carrying amounts presented in the accompanying  consolidated balance sheets.
	Effect of recently issued and recently adopted accounting pronouncements – The following accounting standards, which are not yet effective, are presently being evaluated by BioTime to determine the impact that they might have on its consolidated financial statements.
	In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09 “Revenue from Contracts with Customers” (Topic 606). The guidance of this update effects any entity that either issues contracts with customers or transfers goods or services or enters into contracts for the transfer of non-financial assets. The core principal of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in the amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. To achieve those core principals, the ASU specifies steps that the entity should apply for revenue recognition. The guidance also specifies the accounting for some costs to obtain or fulfill the contract with customer and disclosure requirements to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. For a public entity, ASU No. 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. BioTime is currently evaluating the impact of the adoption of the ASU on its consolidated financial statements.
	In June 2014, the FASB issued ASU No. 2014-12 “Compensation – Stock Compensation” (Topic 718). The ASU provides guidance for accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the requisite service period. That is the case when an employee is eligible to retire or otherwise terminate employment before the end of the period in which a performance target (for example, profitability target) could be achieved and still be eligible to vest in the award if and when the performance target is achieved. The ASU requires a performance target that effects vesting and that could be achieved after the requisite service period be treated as a performance condition. Compensation cost should be recognized in the period in which it becomes probable that such performance condition would be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. For public business entities, the ASU is effective for annual reporting periods beginning after December 15, 2015, and interim periods therein. Early application is permitted. BioTime is in the process of evaluating the impact of adoption of the ASU on its consolidated financial statements.
	In August 2014, the FASB issued ASU No. 2014-15 “Presentation of Financial Statements – Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern” requiring management to evaluate on a regular basis whether any conditions or events have arisen that could raise substantial doubt about the entity’s ability to continue as a going concern. The guidance 1) provides a definition for the term “substantial doubt,” 2) requires an evaluation every reporting period, interim periods included, 3) provides principles for considering the mitigating effect of management’s plans to alleviate the substantial doubt, 4) requires certain disclosures if the substantial doubt is alleviated as a result of management’s plans, 5) requires an express statement, as well as other disclosures, if the substantial doubt is not alleviated, and 6) requires an assessment period of one year from the date the financial statements are issued. The standard is effective for BioTime’s reporting year ending December 31, 2016, and interim periods thereafter. Early adoption is permitted. BioTime does not expect the adoption of this guidance to have a material impact on its financial statements.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2014
Inventory [Abstract]
Inventory	3. Inventory
	BioTime held $253,227 and $165,771 of inventory of raw materials and finished goods products on-site at its corporate headquarters in Alameda, California at December 31, 2014 and 2013, respectively. Finished goods products of $12,795 and $12,923 were held by a third party on consignment at December 31, 2014 and 2013, respectively.

Equipment

Equipment	12 Months Ended
	Dec. 31, 2014
Equipment [Abstract]
Equipment	4. Equipment
	At December 31, 2014 and 2013, equipment, furniture and fixtures, and construction in progress were comprised of the following:
		2014			2013
	Equipment, furniture and fixtures	$	4,870,516		$	4,431,586
	Construction in progress		405,730			-
	Accumulated depreciation		(2,418,400	)		(1,433,853	)
	Equipment net of accumulated depreciation	$	2,857,846		$	2,997,733
	Equipment, furniture and fixtures, and construction in progress at December 31, 2014 include $115,000 financed by capital lease borrowings in June 2014 and $405,730 of construction in progress for Asterias’ Fremont facility. Depreciation expense amounted to $1,050,651 and $656,759 for the years ended December 31, 2014 and 2013, respectively. The difference between the depreciation expense recognized in the consolidated statement of operations and the increase in accumulated depreciation of $984,547 per the consolidated balance sheet is partially attributed to the sale of partially depreciated assets and foreign currency rates.
	Construction in progress
	Construction in progress of $405,730 as of December 31, 2014 entirely relates to the improvements for Asterias' Fremont facility. Under the terms of the lease agreement, the landlord will provide Asterias with a tenant improvement allowance of $4,400,000, which Asterias is using to construct a laboratory and production facility that can be used to produce human embryonic stem cell and related products under current good manufacturing procedures (cGMP). See also Note 15.

Intangible_assets

Intangible assets	12 Months Ended
	Dec. 31, 2014
Intangible assets [Abstract]
Intangible assets	5. Intangible assets
	At December 31, 2014 and 2013, intangible assets and accumulated intangible assets were comprised of the following:
		2014			2013
	Intangible assets	$	52,562,549		$	54,719,918
	Accumulated amortization		(13,714,153	)		(8,511,833	)
	Intangible assets, net	$	38,848,396		$	46,208,085
	BioTime amortizes its intangible assets over an estimated period of 10 years on a straight line basis. BioTime recognized $7,359,690 and $ 3,295,716 in amortization expense of intangible assets during the years ended December 31, 2014 and 2013, respectively. As further discussed in Note 14, Asterias recorded an adjustment to reduce the gross cost of the intangible assets  by $2,157,369 with a corresponding reduction to the accumulated amortization balance of $269,671, resulting in an additional amortization expense of $1,887,698 included in the statements of operations for the year ended December 31, 2014.
	Amortization of intangible assets for periods subsequent to December 31, 2014 is as follows:
	Year Ended	Amortization
	December 31,	Expense
	2015	$	5,256,255
	2016		5,256,255
	2017		5,256,255
	2018		5,256,255
	2019		5,256,255
	Thereafter		12,567,121
	Total	$	38,848,396

Royalty_Obligation_and_Deferre

Royalty Obligation and Deferred License Fees	12 Months Ended
	Dec. 31, 2014
Royalty Obligation and Deferred License Fees [Abstract]
Royalty Obligation and Deferred License Fees	6. Royalty Obligation and Deferred License Fees
	BioTime amortizes deferred license fees over the estimated useful lives of the licensed technologies or licensed research products. BioTime is applying a 10 year estimated useful life to the technologies and products that it is currently licensing. The estimation of the useful life of any technology or product involves a significant degree of inherent uncertainty, since the outcome of research and development or the commercial life a new product cannot be known with certainty at the time that the right to use the technology or product is acquired. BioTime will review its amortization schedules for impairments that might occur earlier than the original expected useful lives.
	WARF License—Research Products
	On January 3, 2008, BioTime entered into a Commercial License and Option Agreement with Wisconsin Alumni Research Foundation (“WARF”). The WARF license permits BioTime to use certain patented and patent pending technology belonging to WARF, as well as certain stem cell materials, for research and development purposes, and for the production and marketing of products used as research tools, including in drug discovery and development. BioTime or ReCyte Therapeutics will pay WARF royalties on the sale of products and services using the technology or stem cells licensed from WARF. The royalty will range from 2% to 4%, depending on the kind of products sold. The royalty rate is subject to certain reductions if BioTime also becomes obligated to pay royalties to a third party in order to sell a product. The $295,000 licensing fees less accumulated amortization of $151,083 and $121,583 were included in deferred license fees in BioTime’s consolidated balance sheet as of December 31, 2014 and 2013, respectively.
	ReCyte Therapeutics Licenses from Ocata
	On July 10, 2008, ReCyte Therapeutics entered into a License Agreement with Advanced Cell Technology, Inc., now Ocata Therapeutics, Inc. (“Ocata”) under which ReCyte Therapeutics acquired exclusive worldwide rights to use Ocata’s technology for methods to accelerate the isolation of novel cell strains from pluripotent stem cells. ReCyte subsequently assigned the license to BioTime. ReCyte Therapeutics paid Ocata a $250,000 license fee and will pay an 8% royalty on sales of products, services, and processes that utilize the licensed technology. Once a total of $1,000,000 of royalties has been paid, no further royalties will be due. The license will expire in twenty years or upon the expiration of the last to expire of the licensed patents, whichever is later. The $250,000 license fee less accumulated amortization of $159,917 and $134,917 are included in deferred license fees in BioTime’s consolidated balance sheet as of December 31, 2014 and 2013, respectively.
	On August 15, 2008, ReCyte Therapeutics entered into a License Agreement and a Sublicense Agreement with Ocata under which ReCyte Therapeutics acquired world-wide rights to use an array of Ocata technology (the “Ocata License”) and technology licensed by Ocata from affiliates of Kirin Pharma Company, Limited (the “Kirin Sublicense”). The Ocata License and Kirin Sublicense permit the commercialization of products in human therapeutic and diagnostic product markets. The technology licensed by ReCyte Therapeutics covers methods to transform cells of the human body, such as skin cells, into an embryonic state in which the cells will be pluripotent. Under the Ocata License, ReCyte Therapeutics paid Ocata a $200,000 license fee and will pay a 5% royalty on sales of products, services, and processes that utilize the licensed Ocata technology, and 20% of any fees or other payments (other than equity investments, research and development costs, loans and royalties) received by ReCyte Therapeutics from sublicensing the Ocatatechnology to third parties. Once a total of $600,000 of royalties has been paid, no further royalties will be due. The license will expire in twenty years or upon the expiration of the last-to-expire of the licensed patents, whichever is later. The $200,000 license fee payment less accumulated amortization of $126,667 and $106,667 are included in deferred license fees in BioTime’s consolidated balance sheet as of December 31, 2014 and 2013.
	Under the Kirin Sublicense, ReCyte Therapeutics has paid Ocata a $50,000 license fee and will pay a 3.5% royalty on sales of products, services, and processes that utilize the licensed Ocata technology, and 20% of any fees or other payments (other than equity investments, research and development costs, loans and royalties) received by ReCyte Therapeutics from sublicensing the Kirin Technology to third parties. ReCyte Therapeutics will also pay to Ocata or to an affiliate of Kirin Pharma Company, Limited (“Kirin”), annually, the amount, if any, by which royalties payable by Ocata under its license agreement with Kirin are less than the $50,000 annual minimum royalty due. Those payments by ReCyte Therapeutics will be credited against other royalties payable to Ocata under the Kirin Sublicense. The license will expire upon the expiration of the last to expire of the licensed patents, or May 9, 2016 if no patents are issued. The $50,000 license fee payment less accumulated amortization of $31,667 and $26,667 are included in deferred license fees in BioTime’s consolidated balance sheet as of December 31, 2014 and 2013 respectively.
	OncoCyte License from SBMRI
	Through BioTime’s acquisition of the assets of Cell Targeting, Inc. during March 2011, BioTime acquired a royalty-bearing, exclusive, worldwide license from the Sanford-Burnham Medical Research Institute (“SBMRI”) to use certain patents pertaining to homing peptides for preclinical research investigations of cell therapy treatments, and to enhance cell therapy products for the treatment and prevention of disease and injury in conjunction with BioTime’s own proprietary technology or that of a third party. BioTime assigned the SBMRI license to OncoCyte during July 2011. OncoCyte will pay SBMRI a royalty of 4% on the sale of pharmaceutical products, and 10% on the sale of any research-use products that OncoCyte develops using or incorporating the licensed technology; and 20% of any payments OncoCyte receives for sublicensing the patents to third parties. The royalties payable to SBMRI may be reduced by 50% if royalties or other fees must be paid to third parties in connection with the sale of any products. An annual license maintenance fee is payable each year during the term of the license, and after commercial sales of royalty bearing products commence, the annual fee will be credited towards OncoCyte's royalty payment obligations for the applicable year. OncoCyte will reimburse SBMRI for 25% of the costs incurred in filing, prosecuting, and maintaining patent protection, subject to OncoCyte’s approval of the costs. OncoCyte incurred no royalty expenses to date as of December 31, 2014.
	Cell Cure Neurosciences License from Hadasit
	Cell Cure Neurosciences has entered into an Amended and Restated Research and License Agreement with Hadasit Medical Research Services and Development, Ltd. (“Hadasit”) under which Cell Cure Neurosciences received an exclusive license to use certain of Hadasit’s patented technologies for the development and commercialization for hES cell-derived cell replacement therapies for retinal degenerative diseases. Cell Cure Neurosciences paid Hadasit 249,058 New Israeli Shekels (approximately US$63,860) as a reimbursement for patent expenses incurred by Hadasit, and pays Hadasit quarterly fees for research and product development services under a related Product Development Agreement.
	If Cell Cure Neurosciences commercializes OpRegen® or OpRegen®-Plus itself or sublicenses the Hadasit patents to a third party for the completion of development or commercialization of OpRegen® or OpRegen®-Plus, Cell Cure Neurosciences will pay Hadasit a 5% royalty on sales of products that utilize the licensed technology. Cell Cure Neurosciences will also pay sublicensing fees ranging from 10% to 30% of any payments Cell Cure Neurosciences receives from sublicensing the Hadasit patents to companies. Commencing in January 2017, Hadasit will be entitled to receive an annual minimum royalty payment of $100,000 that will be credited toward the payment of royalties and sublicense fees otherwise payable to Hadasit during the calendar year. If Cell Cure Neurosciences or a sublicensee paid royalties during the previous year, Cell Cure Neurosciences may defer making the minimum royalty payment until December and will be obligated to make the minimum annual payment to the extent that royalties and sublicensing fee payments made during that year are less than $100,000.
	If Cell Cure Neurosciences or a sublicensee conducts clinical trials of OpRegen® or OpRegen®-Plus, Hadasit will be entitled to receive certain payments from Cell Cure Neurosciences upon the first attainment of certain clinical trial milestones in the process of seeking regulatory approval to market a product developed by Cell Cure Neurosciences using the licensed patents. Hadasit will receive $250,000 upon the enrollment of patients in the first Phase I clinical trial, $250,000 upon the submission of Phase II clinical trial data to a regulatory agency as part of the approval process, and $1 million upon the enrollment of the first patient in the first Phase III clinical trial.
	BioTime License for the University of Utah
	Through the merger of Glycosan into OrthoCyte during March 2011, BioTime acquired a license from the University of Utah to use certain patents in the production and sale of certain hydrogel products. Under the License Agreement, the scope of which was expanded by an amendment during August 2012, BioTime will pay a 3% royalty on sales of products and services performed that utilize the licensed patents. Commencing in 2014, BioTime will be obligated to pay minimum royalties to the extent that actual royalties on products sales and services utilizing the patents are less than the minimum royalty amount. The minimum royalty amounts were $2,500 in 2014 and will be $30,000 each year thereafter during the term of the License Agreement. BioTime shall also pay the University of Utah 30% of any sublicense fees or royalties received under any sublicense of the licensed patents.
	BioTime will pay the University of Utah $5,000 upon the issuance of each of the first five licensed patents issued in the U.S., subject to reduction to $2,500 for any patent that the University has licensed to two or more other licensees for different uses. BioTime will also pay a $225,000 milestone fee within six months after the first sale of a “tissue engineered product” that utilizes a licensed patent. A tissue engineered product is defined as living human tissues or cells on a polymer platform, created at a place other than the point-of-care facility, for transplantation into a human patient.
	Asterias License from WARF
	Asterias has entered into a Non-Exclusive License Agreement with WARF under which Asterias was granted a worldwide non-exclusive license under certain WARF patents and WARF-owned embryonic stem cell lines to develop and commercialize therapeutic, diagnostic and research products. The licensed patents include patents covering primate embryonic stem cells as compositions of matter, as well as methods for growth and differentiation of primate embryonic stem cells. The licensed stem cell lines include the H1, H7, H9, H13 and H14 hES cell lines.
	In consideration of the rights licensed, Asterias has agreed to pay WARF an upfront license fee, payments upon the attainment of specified clinical development milestones, royalties on sales of commercialized products, and, subject to certain exclusions, a percentage of any payments that Asterias may receive from any sublicenses that it may grant to use the licensed patents or stem cell lines.
	The license agreement will terminate with respect to licensed patents upon the expiration of the last licensed patent to expire. Asterias may terminate the license agreement at any time by giving WARF prior written notice. WARF may terminate the license agreement if payments of earned royalties, once begun, cease for a specified period of time or if Asterias and any third parties collaborating or cooperating with Asterias in the development of products using the licensed patents or stem cell lines fail to spend a specified minimum amount on research and development of products relating to the licensed patents or stem cell lines for a specified period of time. WARF also has the right to terminate the license agreement if Asterias breaches the license agreement or becomes bankrupt or insolvent or if any of the licensed patents or stem cell lines are offered to creditors
	Asterias License from the University of California
	Geron Corporation (“Geron”) assigned to Asterias an Exclusive License Agreement with The Regents of the University of California for patents covering a method for directing the differentiation of multipotential hES cells to glial-restricted progenitor cells that generate pure populations of oligodendrocytes for remyelination and treatment of spinal cord injury. Pursuant to this agreement, Asterias has an exclusive worldwide license under such patents, including the right to grant sublicenses, to create products for biological research, drug screening, and human therapy using the licensed patents. Under the license agreement, Asterias will be obligated to pay the university a royalty of 1% from sales of products that are covered by the licensed patent rights, and a minimum annual royalty of $5,000 starting in the year in which the first sale of a product covered by any licensed patent rights occurs, and continuing for the life of the applicable patent right under the agreement. The royalty payments due are subject to reduction, but not by more than 50%, to the extent of any payments that Asterias may be obligated to pay to a third party for the use of patents or other intellectual property licensed from the third party in order to make, have made, use, sell, or import products or otherwise exercise its rights under the Exclusive License Agreement. Asterias will be obligated to pay the university 7.5% of any proceeds, excluding debt financing and equity investments, and certain reimbursements, that its receives from sublicensees, other than Asterias’ affiliates and joint ventures relating to the development, manufacture, purchase, and sale of products, processes, and services covered by the licensed patent. The license agreement will terminate on the expiration of the last-to-expire of the university's issued licensed patents. If no further patents covered by the license agreement are issued, the license agreement would terminate in 2024. The university may terminate the agreement in the event of Asterias’ breach of the agreement. Asterias can terminate the agreement upon 60 days' notice.
	Asterias Sublicenes from Geron
	Asterias has received from Geron an exclusive sublicense under certain patents owned by the University of Colorado’s University License Equity Holdings, Inc. relating to telomerase (the “Telomerase Sublicense”). The Telomerase Sublicense entitles Asterias to use the technology covered by the patents in the development of AST-VAC1 and AST-VAC2 as immunological treatments for cancer. Under the Telomerase Sublicense, Asterias paid Geron a one-time upfront license fee of $65,000, and will pay Geron an annual license maintenance fee of $10,000 due on each anniversary of the effective date of the Telomerase Sublicense, and a 1% royalty on sales of any products that Asterias may develop and commercialize that are covered by the sublicensed patents. The Telomerase Sublicense will expire concurrently with the expiration of Geron’s license. That license will terminate during April 2017 when the licensed patents expire. The Telomerase Sublicense may also be terminated by Asterias by giving Geron 90 days written notice, by Asterias or by Geron if the other party breaches its obligations under the sublicense agreement and fails to cure their breach within the prescribed time period, or by Asterias or by Geron upon the filing or institution of bankruptcy, reorganization, liquidation or receivership proceedings, or upon an assignment of a substantial portion of the assets for the benefit of creditors by the other party.
	As of December 31, 2014, amortization of deferred license fees was as follows:
	Year Ended	Deferred License
	December 31,	Fees
	2015	$	109,500
	2016		109,500
	2017		109,500
	2018		73,667
	2019		24,083
	Thereafter		20,083
	Total	$	446,333
	The current portion in the amount of $109,500 is included in prepaid expenses and other current assets. Noncurrent portion is included in $336,833, deferred license and consulting fees.

Accounts_Payable_and_Accrued_L

Accounts Payable and Accrued Liabilities	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Liabilities [Abstract]
Accounts Payable and Accrued Liabilities	At December 31, 2014 and 2013, accounts payable and accrued liabilities consist of the following:
		December 31,
		2014		2013
	Accounts payable	$	2,296,645	$	3,434,748
	Accrued expenses		3,125,023		2,296,146
	Accrued bonuses		964,189		600,000
	Other current liabilities		417,316		391,730
	Total	$	6,803,173	$	6,722,624

Related_Party_Transactions_and

Related Party Transactions and Related Party Convertible Debt	12 Months Ended
	Dec. 31, 2014
Related Party Transactions and Related Party Convertible Debt [Abstract]
Related Party Transactions and Related Party Convertible Debt	8. Related Party Transactions and Related Party Convertible Debt
	BioTime currently pays $5,050 per month for the use of approximately 900 square feet of office space in New York City, which is made available to BioTime on a month-by-month basis by one of its directors at his cost for use in conducting meetings and other business affairs.
	During June 2014, Asterias sold 5,000,000 of its BioTime common shares with warrants to purchase 5,000,000 shares of Asterias common stock to two investors for $12,500,000 in cash. Broadwood Partners, L.P., BioTime’s largest shareholder, purchased 1,000,000 of the BioTime common shares with 1,000,000 Asterias warrants. One of BioTime’s directors, Neal C. Bradsher, is President of Broadwood Partners, L.P., the investment manager of Broadwood Partners, L.P., and one of Asterias’ directors, Richard T. LeBuhn, is Senior Vice President of Broadwood Capital, Inc. The other 4,000,000 BioTime common shares with 4,000,000 Asterias warrants were purchased by a trust previously established by George Karfunkel, which then distributed the BioTime shares and Asterias warrants to the trust beneficiaries. Mr. Karfunkel beneficially owns more than 5% of the outstanding common shares of BioTime.
	In July and September 2014, Cell Cure Neurosciences issued certain convertible notes (the “Convertible Notes”) to two Cell Cure Neurosciences shareholders other than BioTime in the principal amount of $469,247. The Cell Cure Neurosciences shareholders who acquired Convertible Notes are considered related parties under ASC 850, Related Party Disclosures. The functional currency of Cell Cure Neurosciences is the Israeli New Shekel, however the Convertible Notes are payable in United States dollars. The Convertible Notes bear a stated interest rate of 3% per annum. The total outstanding principal balance of the Convertible Notes, with accrued interest, is due and payable on various maturity dates in July and September 2017. The outstanding principal balance of the Convertible Notes with accrued interest is convertible into Cell Cure Neurosciences ordinary shares at a fixed conversion price of $20.00 per share, at the election of the holder, at any time prior to maturity. Any conversion of the Convertible Notes must be settled with Cell Cure Neurosciences ordinary shares and not with cash. The conversion feature of the Convertible Notes is not accounted for as an embedded derivative under the provisions of ASC 815, Derivatives and Hedging since it is not a freestanding financial instrument and the underlying Cell Cure Neurosciences ordinary shares are not readily convertible into cash. Accordingly, the Convertible Notes are accounted for under ASC 470-20, Debt with Conversion and Other Options. Under ASC 470-20, BioTime determined that a beneficial conversion feature (“BCF”) was present on the issuance dates of the Convertible Notes.
	A conversion feature is beneficial if, on the issuance dates, the effective conversion price is less than the fair value of the issuer’s capital stock. Since the effective conversion price of $20.00 per share is less than the estimated $41.00 per share fair value of Cell Cure Neurosciences ordinary shares on the dates the Convertible Notes were issued, a beneficial conversion feature equal to the intrinsic value is present. In accordance with ASC 470-20-30-8, if the intrinsic value of the BCF is greater than the proceeds allocated to the convertible instrument, the amount of the discount assigned to the BCF is limited to the amount of the proceeds allocated to the convertible instrument. The BCF is recorded as an addition to equity with a corresponding reduction to the carrying value of the convertible debt instrument. In the case of the Convertible Notes, this reduction represents a debt discount equal to the principal amount of $469,247 on the issuance dates. This debt discount will be amortized to interest expense using the effective interest method over the three-year term of the debt, representing an approximate effective annual interest rate of 23%. As of December 31, 2014, the carrying value of the Convertible Notes was $60,237, comprised of principal and accrued interest of $472,834, net of unamortized debt discount of $412,597.
	During October 2014, BioTime sold 9,431,398 common shares for $29,425,962 to certain investors in a transaction registered under the Securities Act of 1933, as amended. The $3.12 price per share was the closing price of BioTime common shares on the NYSE MKT on the date on which BioTime and the investors agreed upon the purchase price. Broadwood Partners, L.P., purchased 4,040,523 shares, and three of BioTime’s directors purchased 96,150 shares in the offering.
	During June 2014, Asterias sold 200,000 shares of Asterias common stock to its Chief Executive Officer, who was also a director of BioTime at that time, for $468,000 in cash.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2014
Shareholders' Equity [Abstract]
Shareholders' Equity	9. Shareholders' Equity
	BioTime has issued warrants to purchase its common shares. Activity related to warrants in 2014 and 2013 is presented in the table below:
			Number of			Per share			Weighted Average
			Warrants			exercise			Exercise
						price			Price
	Outstanding, January 1, 2013			556,613		$	10		$	10
	Issued in 2013			9,195,002			5			5
	Outstanding, December 31, 2013			9,751,615		$	5.00 – 10.00		$	5.29
	Exercised in 2014			(556,613	)		10			10
	Retired in 2014			(313	)		5			5
	Exercised in 2014			(10	)		5			5
	Outstanding, December 31, 2014			9,194,679		$	5		$	5
	At December 31, 2014, 9,194,679 warrants to purchase common shares with a weighted average exercise price of $5.00 per share and a weighted average remaining contractual life of 3.42 years were outstanding.
	At December 31, 2013, 9,751,615 warrants to purchase common shares with a weighted average exercise price of $5.29 per share and a weighted average remaining contractual life of 4.19 years were outstanding.
	A summary of all option activity under the subsidiary option plans (See Note 10) for the years ended December 31, 2014 and 2013 is as follows:
			Options			Number of			Weighted
			Available for			Options			Average
			Grant			Outstanding			Exercise
									Price
	1-Jan-13			6,041,556			7,816,413		$	0.93
	Increase option pool			500,000			-			-
	Granted in 2013			(4,434,995	)		4,434,995			2.11
	Expired/Forfeited/Exercised in 2013			785,000			(785,000	)		1.95
	31-Dec-13			2,891,561			11,466,408		$	1.32
	Granted in 2014			(1,603,167	)		1,603,167			6.59
	Expired/Forfeited/Exercised in 2014			1,368,904			(1,368,904	)		2.28
	31-Dec-14			2,657,298			11,700,671		$	1.98
	Preferred Shares
	BioTime is authorized to issue 2,000,000 shares of preferred stock. The preferred shares may be issued in one or more series as the board of directors may by resolution determine. The board of directors is authorized to fix the number of shares of any series of preferred shares and to determine or alter the rights, preferences, privileges, and restrictions granted to or imposed on the preferred shares as a class, or upon any wholly unissued series of any preferred shares. The board of directors may, by resolution, increase or decrease (but not below the number of shares of such series then outstanding) the number of shares of any series of preferred shares subsequent to the issue of shares of that series.
	As of December 31, 2014, BioTime had 70,000 outstanding shares of Series A Convertible Preferred Stock (“Series A Preferred Stock”). The Series A Preferred Stock carries a cumulative annual 3% preferred dividend or $1.50 per share, in preference to BioTime common shares. Each share of Series A Preferred Stock is convertible, at the election of the holder, into BioTime common shares at a conversion price of $4.00 per share, a current conversion ratio of 12.5 common shares for each share of Series A Preferred Stock.
	In addition to the preferred dividend, the Series A Preferred Stock will be entitled to participate with BioTime common shares in any dividends or distributions on common shares (other than dividends and distributions of common shares resulting in an adjustment of the conversion price) as if all shares of Series A Preferred Stock were then converted into common shares.
	All outstanding Series A Preferred Stock will automatically be converted into common shares on March 4, 2019, or if holders of a majority of the outstanding shares of Series A Preferred Stock, voting as a class, approve or consent to a conversion. The conversion price is subject to prorata adjustment in the event of a subdivision or reclassification of the common shares into a greater number of shares, a stock dividend paid in common shares, or a stock combination or reclassification of the common shares into a smaller number of shares.
	The Series A Preferred Stock will be entitled to vote with common shares on all matters submitted to common shareholders for approval. Each share of Series A Preferred Stock will be entitled to a number of votes equal to the number of common shares into which it could then be converted. The Series A Preferred Stock will also vote as a separate class on certain matters affecting those shares.
	In the event of a liquidation or dissolution of BioTime, holders of Series A Preferred Stock will be entitled to receive payment of any accrued but unpaid preferred dividends before any assets may be distributed to holders of common shares. After payment of the accrued dividends, the Series A Preferred Stock will participate with the common shares in the distribution of any assets available to shareholders, as if the Series A Preferred Stock was then converted into common shares.
	Common shares
	BioTime is authorized to issue 125,000,000 common shares with no par value. As of December 31, 2014, BioTime had 83,121,698 issued and 78,227,756 outstanding common shares. As of December 31, 2013, BioTime had 67,412,139 issued and 56,714,424 outstanding common shares. The difference of 4,893,942 and 10,697,715 common shares as of December 31, 2014 and 2013, respectively is attributed to treasury shares held by BioTime subsidiaries which are accounted for as treasury stock on the consolidated balance sheet.
	Significant common share transactions during the year ended December 31, 2014 are as follows:
		·	During 2014 BioTime and certain subsidiaries sold 5,545,160 BioTime common shares for gross proceeds of $17,380,668 at prevailing market prices through Cantor Fitzgerald & Co. (“Cantor”) acting as sales agent. Sales of BioTime common through Cantor for BioTime’s own account were made under a Controlled Equity OfferingSM Sales Agreement between BioTime and Cantor. The proceeds of the sale of BioTime shares by BioTime’s subsidiaries belong to those subsidiaries.
		·	During June 2014, Asterias sold 5,000,000 of its BioTime common shares with warrants to purchase 5,000,000 shares of Asterias Series B common stock to two investors for $12,500,000 in cash. Broadwood Partners, L.P., purchased 1,000,000 of the BioTime common shares with 1,000,000 Asterias warrants and a trust previously established by George Karfunkel purchased 4,000,000 of the BioTime common shares with 4,000,000 Asterias warrants.
		·	During October 2014, BioTime sold 9,431,398 common shares for $29,425,962 in a transaction registered under the Securities Act. The $3.12 price per share was the closing price of BioTime common shares on the NYSE MKT on the date on which BioTime and the investors agreed upon the purchase price. See also Note 8.
	Significant common share transactions during the year ended December 31, 2013 are as follows:
		·	In January 2013, as additional consideration for the lease for an office and research facility located in Menlo Park, California, BioTime issued to the landlord 73,553 BioTime common shares having a market value of $242,726, determined based upon the average closing price of BioTime common shares on the NYSE MKT for a designated period of time prior to the signing of the lease. For accounting purposes, these shares were revalued at $253,758 which was based on the closing price of BioTime common shares on the NYSE MKT on the date the lease was fully executed at which time the shares were issued.
		·	In January 2013, BioTime and a private investor entered into a Stock and Warrant Purchase Agreement under which BioTime received $5,000,000 for the sale of 1,350,000 BioTime common shares and warrants to purchase 649,999 additional BioTime common shares at an exercise price of $5.00 per share.
		·	In January 2013, in accordance with a November 1, 2012 Share Purchase Agreement between BioTime and Cell Cure Neurosciences, BioTime purchased 87,456 Cell Cure Neurosciences ordinary shares in exchange for 906,735 of BioTime common shares.
		·	In June 2013, BioTime sold an aggregate of 2,180,016 common shares and 545,004 warrants to purchase common shares, in "units" with each unit consisting of one common share and one-quarter of a warrant, at an offering price of $4.155 per unit, to certain investors through an offering registered under the Securities Act. BioTime received gross proceeds of $9,057,967 from the sale of the common shares and warrants. The warrants have an initial exercise price of $5.00 per share and are exercisable during the five year period beginning on the date of issuance, June 6, 2013.
		·	In October 2013, BioTime issued 8,902,077 common shares and warrants to purchase 8,000,000 common shares to Asterias under the Asset Contribution Agreement.
		·	During 2013 BioTime and certain of its subsidiaries sold 3,665,646 BioTime common shares for gross proceeds of $15,722,339 at prevailing market prices through Cantor acting as sales agent. Sales by BioTime for its own account were made through its Controlled Equity OfferingSM Sales Agreement with Cantor. The proceeds of the sale of BioTime shares by its subsidiaries belong to those subsidiaries.

Stock_Option_Plans

Stock Option Plans	12 Months Ended
	Dec. 31, 2014
Stock Option Plans [Abstract]
Stock Option Plans	10. Stock Option Plans
	During 2002, BioTime adopted the 2002 Employee Stock Option Plan (the “2002 Plan”), which was amended in 2004, 2007, and 2009 to reserve additional common shares for issuance under options or restricted stock awards granted to eligible persons. The 2002 Plan expired during September 2012 and no additional grants of options or awards of restricted stock may be made under the 2002 Plan.
	During December 2012, BioTime’s Board of Directors approved the 2012 Equity Incentive Plan (the “2012 Plan”) under which BioTime has reserved 4,000,000 common shares for the grant of stock options or the sale of restricted stock. No options may be granted under the 2012 Plan more than ten years after the date upon which the 2012 Plan was adopted by the Board of Directors, and no options granted under the 2012 Plan may be exercised after the expiration of ten years from the date of grant. Under the 2012 Plan, options to purchase common shares may be granted to employees, directors and certain consultants at prices not less than the fair market value at date of grant, subject to certain limited exceptions for options granted in substitution of other options. Options may be fully exercisable immediately, or may be exercisable according to a schedule or conditions specified by the Board of Directors or the Compensation Committee. The 2012 Plan also permits BioTime to award restricted stock for services rendered or to sell common shares to employees subject to vesting provisions under restricted stock agreements that provide for forfeiture of unvested shares upon the occurrence of specified events under a restricted stock award agreement. BioTime may permit employees or consultants, but not officers or directors, who purchase stock under restricted stock purchase agreements, to pay for their shares by delivering a promissory note that is secured by a pledge of their shares.
	BioTime may also grant stock appreciation rights (“SARs”) and hypothetical units issued with reference to BioTime common shares (“Restricted Stock Units”) under the Plan. An SAR is the right to receive, upon exercise, an amount payable in cash or shares or a combination of shares and cash, as determined by the Board of Directors or the Compensation Committee, equal to the number of shares subject to the SAR that is being exercised multiplied by the excess of (a) the fair market value of a BioTime common share on the date the SAR is exercised, over (b) the exercise price specified in the SAR Award agreement.
	The terms and conditions of a grant of Restricted Stock Units will be determined by the Board of Directors or Compensation Committee. No shares of stock will be issued at the time a Restricted Stock Unit is granted, and BioTime will not be required to set aside a fund for the payment of any such award. A recipient of Restricted Stock Units will have no voting rights with respect to the Restricted Stock Units. Upon the expiration of the restrictions applicable to a Restricted Stock Unit, BioTime will either issue to the recipient, without charge, one common share per Restricted Stock Unit or cash in an amount equal to the fair market value of one common share.
	The following table summarizes stock-based compensation expense related to employee and director stock options awards for the years ended December 31, 2014, 2013, and 2012, which was allocated as follows:
		Year Ended December 31,
	All stock-based compensation expense:	2014					2013					2012
	Research and Development	$	1,309,703				$	829,938				$	815,052
	General and Administrative		3,145,717					2,214,836					1,028,910
	All stock-based compensation expense included in expenses	$	4,455,420				$	3,044,774				$	1,843,962
	As of December 31, 2014, total unrecognized compensation costs related to unvested stock options was $8,388,639, which is expected to be recognized as expense over a weighted average period of approximately 6.93 years.
	The table above does not include $173,100 of stock-based compensation to a consultant in 2013.
	The weighted-average estimated fair value of stock options granted during the years ended December 31, 2014 and 2013 was $3.43 and $4.13 per share respectively, using the Black-Scholes Merton model with the following weighted-average assumptions:
		Year Ended
		December 31,
		2014				2013
	Expected life (in years)		6.67				6.68
	Risk-free interest rates		2.19	%			1.51	%
	Volatility		83.2	%			95.22	%
	Dividend yield		0	%			0	%
	General Option Information
	A summary of all option activity under the 2002 Plan and the 2012 Plan for the years ended December 31, 2014 and 2013 is as follows:
		Options					Number of					Weighted
		Available for					Options					Average
		Grant					Outstanding					Exercise
												Price
	1-Jan-13		3,745,000					3,681,301				$	1.96
	Granted under 2012 Plan		(1,585,000	)				1,585,000					4.13
	Exercised		-					(20,000	)				2.3
	Forfeited/expired under 2002 Plan		-					(524,166	)				4.01
	Forfeited/expired under 2012 Plan		155,000					(155,000	)				4.18
	31-Dec-13		2,315,000					4,567,135				$	2.71
	Granted under 2012 Plan		(2,170,000	)				2,170,000					3.54
	Exercised		-					(2,060,400	)				0.58
	Forfeited/expired under 2002 Plan		-					(179,491	)				4.32
	Forfeited/expired under 2012 Plan		522,918					(522,918	)				3.72
	31-Dec-14		667,918					3,974,326				$	4.04
	Additional information regarding options outstanding as of December 31, 2014 is as follows:
					Options Outstanding									Options Exercisable
	Range of Exercise		Number			Weighted Avg.				Weighted Avg.						Number	Weighted Avg.
	Prices		Outstanding			Remaining				Exercise Price						Exercisable	Exercise Price
						Contractual Life
						(years)
	2.52-8.58		3,974,326				5.57			$	4.04					1,716,099	$	4.48
	$2.52-8.58		3,974,326				5.57			$	4.04					1,716,099	$	4.48
	Subsidiary Stock Option Plans
	During 2013 Asterias adopted an Equity Incentive Plan that has substantially the same operative provisions as BioTime’s 2012 Plan except that it permits the sale or grant of up to 4,500,000 shares of Asterias common stock.
	During 2011, BioTime’s subsidiary, LifeMap Sciences adopted a stock option plan that has substantially the same operative provisions as the BioTime 2002 Stock Option Plan. The LifeMap Sciences stock option plan authorized the sale of up to 8,000,000 shares of its common stock through the exercise of stock options or under restricted stock purchase agreements. During 2012, the LifeMap Sciences stock option plan was amended to reflect a 1 for 4 reverse stock split and a change in plan. As a result, the total number of shares that may be issued under the plan was adjusted to 1,842,168.
	During 2010, BioTime’s subsidiaries OncoCyte, OrthoCyte, ReCyte Therapeutics, and BioTime Asia adopted stock option plans that have substantially the same operative provisions as the BioTime 2002 Stock Option Plan. The OncoCyte, OrthoCyte and ReCyte Therapeutics stock option plans each authorize the sale of up to 4,000,000 shares of the applicable subsidiary’s common stock through the exercise of stock options or under restricted stock purchase agreements. The BioTime Asia stock option plan authorizes the sale of up to 1,600 ordinary shares through the exercise of stock options or under restricted stock purchase agreements. Cell Cure Neurosciences' option plan authorizes the sale of 14,100 ordinary shares through the exercise of stock options.
	During 2013, BioTime’s subsidiary, LifeMap Solutions adopted a stock option plan that has substantially the same operative provisions as the BioTime 2002 Stock Option Plan. The LifeMap Sciences stock option plan authorized the sale of up to 18,667 shares of its common stock through the exercise of stock options or under restricted stock purchase agreements.
					Subsidiary Options Outstanding									Options Exercisable
	Range of Exercise	Number				Weighted Avg.				Weighted Avg.					Number		Weighted Avg.
	Prices	Outstanding				Remaining				Exercise Price					Exercisable		Exercise Price
						Contractual Life (years)
	$0.003-$0.75	5,256,226					4.96			$	0.36				5,091,506		$	0.37
	1.00-1.75	1,986,772					4.87				1.58				1,157,886			1.5
	2.05-2.34	4,361,666					5.53				2.26				2,066,146			2.18
	3.88-6.25	75,000					0.12				0.105				2,708			0.01
	27.00-42.02	7,840					5.8				37.35				7,840			37.35
	500	13,167					0.04				3.31				1,993			0.86
	$0.003-$500.00	11,700,671					5.17			$	1.9				8,328,079		$	1.13

Sales_of_BioTime_Common_Shares

Sales of BioTime Common Shares by Subsidiaries	12 Months Ended
	Dec. 31, 2014
Sales of BioTime Common Shares by Subsidiaries [Abstract]
Sales of BioTime Common Shares by Subsidiaries	11. Sales of BioTime Common Shares by Subsidiaries
	Certain BioTime subsidiaries hold BioTime common shares that the subsidiaries received from BioTime in exchange for capital stock in the subsidiaries. The BioTime common shares held by subsidiaries are treated as treasury stock by BioTime and BioTime does not recognize a gain or loss on the sale of those shares by its subsidiaries. See also Note 9.
	During June 2014, Asterias sold 5,000,000 of its BioTime common shares with warrants to purchase 5,000,000 shares of Asterias Series B common stock to two investors for $12,500,000 in cash. Broadwood Partners, L.P., purchased 1,000,000 of the BioTime common shares with 1,000,000 Asterias warrants and a trust previously established by George Karfunkel purchased 4,000,000 of the BioTime common shares with 4,000,000 Asterias warrants. See also Note 9.

Clinical_Trial_and_Option_Agre

Clinical Trial and Option Agreement and CIRM Grant Award	12 Months Ended
	Dec. 31, 2014
Clinical Trial and Option Agreement and CIRM Grant Award [Abstract]
Clinical Trial and Option Agreement and CIRM Grant Award [Text Block]	12. Clinical Trial and Option Agreement and CIRM Grant Award
	During September 2014, Asterias entered into a Clinical Trial and Option Agreement (the “CRUK Agreement”) with Cancer Research UK (“CRUK”) and Cancer Research Technology Limited (“CRT”), a wholly-owned subsidiary of CRUK, pursuant to which CRUK has agreed to fund Phase I/IIa clinical development of Asterias’ AST-VAC2 product candidate. Asterias will, at its own cost, complete process development and manufacturing scale-up of the AST-VAC2 manufacturing process and will transfer the resulting cGMP-compatible process to CRUK. CRUK will, at its own cost, manufacture the clinical grade AST-VAC2 and will carry out the Phase I/IIa clinical trial of AST-VAC2 in cancer patients both resected early-stage and advanced forms of lung cancer. Asterias will have an exclusive first option to obtain a license to use the data from the clinical trial. If Asterias exercises that option it will be obligated to make payments upon the execution of the License Agreement, upon the achievement of various milestones, and then royalties on sales of products, and if Asterias sublicenses product development or commercialization rights to a third party, Asterias would pay CRT a share of any sublicense revenues that Asterias receives from the third party,with CRT’s share varying from a high of 40% in the case of a sublicense entered into prior to commencement of a Phase II clinical trial, to substantially lower rates in the case of a sublicense entered into at various later stages of clinical development but prior to completion of a Phase III clinical trial, and as low as 7.5% in the case of a sublicense entered into after completion of a Phase III clinical trial. In connection with the CRUK Agreement, Asterias sublicensed to CRUK for use in the clinical trials and product manufacturing process certain patents that have been licensed or sublicensed to Asterias by third parties. Asterias would also be obligated to make payments to those licensors and sublicensors upon the achievement of various milestones, and then royalties on sales of products if AST-VAC2 is successfully developed and commercialized.
	On October 16, 2014 Asterias signed a Notice of Grant Award (“NGA”) with the California Institute of Regenerative Medicine (“CIRM”), effective October 1, 2014, with respect to a $14.3 million CIRM grant award for clinical development of Asterias' product, AST-OPC1. The NGA includes the terms under which CIRM will release grant funds to Asterias. CIRM will disburse the grant funds to Asterias over four years in accordance with a quarterly disbursement schedule, subject to Asterias' attainment of certain progress and safety milestones. Asterias received the first payment from CIRM in the amount of $916,554 in October 2014.

Share_Exchange_and_Contributio

Share Exchange and Contribution Agreement	12 Months Ended
	Dec. 31, 2014
Share Exchange and Contribution Agreement [Abstract]
Share Exchange and Contribution Agreement	13. Share Exchange and Contribution Agreement
	In accordance with the License and Research Assignment Agreement dated May 14, 2012 between Yeda Research and Development Company, Ltd (“Yeda”) and BioTime in connection with the merger of XenneX, Inc. and LifeMap Sciences Yeda was entitled to receive additional shares of LifeMap Sciences common stock as a result of the issuance of additional shares of common stock by LifeMap Sciences during 2012 to permit Yeda to maintain their 3.75% ownership in the issued and outstanding LifeMap Sciences shares on a fully diluted basis. LifeMap Sciences issued Yeda 66,791 shares of LifeMap Sciences common stock with an estimated fair value of $117,000 under that provision of the License and Research Assignment Agreement.

Asset_Contribution_Agreement

Asset Contribution Agreement	12 Months Ended
	Dec. 31, 2014
Asset Contribution Agreement [Abstract]
Asset Contribution Agreement	14. Asset Contribution Agreement
	On January 4, 2013, BioTime and Asterias entered into an Asset Contribution Agreement with Geron pursuant to which BioTime and Geron agreed to concurrently contribute certain assets to Asterias in exchange for shares of Asterias common stock. The transaction closed on October 1, 2013.
	Transfer of BioTime Assets
	Under the Asset Contribution Agreement, BioTime contributed to Asterias 8,902,077 BioTime common shares registered for re-sale under the Securities Act, warrants to subscribe for and purchase 8,000,000 additional BioTime common shares (the “BioTime Warrants”) exercisable for a period of five years at a price of $5.00 per share, subject to pro rata adjustment for certain stock splits, reverse stock splits, stock dividends, recapitalizations and other transactions; a 10% common stock interest in BioTime’s subsidiary OrthoCyte; a 6% ordinary share interest in BioTime’s subsidiary Cell Cure Neurosciences; and a quantity of certain hES cell lines produced under “good manufacturing practices” sufficient to generate master cell banks, and non-exclusive, world-wide, royalty-free licenses to use those cell lines and certain patents pertaining to stem cell differentiation technology for any and all purposes. In return, Asterias issued to BioTime 21,773,340 shares of its Series B common stock, par value $0.0001 per share (“Series B Shares”), and warrants to purchase 3,150,000 Series B Shares, exercisable for a period of three years from the date of issue at an exercise price of $5.00 per share. In addition, BioTime cancelled Asterias’ obligations to repay the principal amount of a loan in the amount of $5,000,000 arising from cash financing provided to Asterias by BioTime during 2013 prior to the closing of the asset contribution transaction under the Asset Contribution Agreement.
	Because Asterias is a subsidiary of BioTime, the transfer of assets from BioTime was accounted for as a transaction under common control. Non-monetary assets received by Asterias were recorded at their historical cost basis amounts with BioTime. Monetary assets were recorded at fair value. The difference between the value of assets contributed by BioTime and the fair value of consideration issued to BioTime was recorded as an additional contribution by BioTime, in additional paid-in capital.
	The assets transferred by BioTime and the related consideration paid were recorded as follows:
	Consideration transferred to BioTime:
	Asterias Series B shares	$	52,164,568
	Warrants to purchase Asterias Series B shares		2,012,481
	Excess of contributed assets’ value over consideration		4,800,063
	Total consideration issued	$	58,977,112
	Assets transferred by BioTime:
	BioTime common shares, at fair value	$	34,985,163
	BioTime Warrants, at fair value		18,276,406
	Cancellation of outstanding obligation to BioTime		5,000,000
	Investment in affiliates, at cost		415,543
	Geron asset acquisition related transaction costs paid by BioTime		300,000
	Total assets transferred	$	58,977,112
	The fair value of the Asterias Series B shares issued was estimated at $2.40 based on the Asterias enterprise value as determined on January 4, 2013, at the time the Asset Contribution Agreement was negotiated and executed by its parties, and as adjusted for subsequent changes in fair values of assets the parties agreed to contribute. The fair value of the warrants to purchase Asterias Series B shares was computed using a Black Scholes Merton option pricing model, which utilized the following assumptions: expected term equal to the contractual term of three years, which is equal to the contractual life of the warrants; risk-free rate of 0.63%; 0% expected dividend yield; 69.62% expected volatility based on the average historical common stock volatility of BioTime and Geron, which were used as Asterias’ common stock does not have a trading history; a stock price of $2.40; and an exercise price of $5.00.
	BioTime common shares were valued at $3.93 using the closing price per BioTime common shares on the NYSE MKT on October 1, 2013. The fair value of the BioTime Warrants was computed using a Black Scholes Merton option pricing model, which utilized the following assumptions: expected term equal to the contractual term of five years, which is equal to the contractual life of the warrants; risk-free rate of 1.42%; 0% expected dividend yield; 77.63% expected volatility based on historical common stock volatility of BioTime; a stock price of $3.93; and an exercise price of $5.00.
	The investment in OrthoCyte and Cell Cure Neurosciences stock represents a non-monetary asset and was recorded at BioTime’s historical cost because BioTime is a common parent to Asterias and those two BioTime subsidiaries.
	Geron Assets Acquisition
	Under the Asset Contribution Agreement, Geron contributed to Asterias certain patents, patent applications, trade secrets, know-how and other intellectual property rights with respect to the technology of Geron directly related to the research, development and commercialization of certain products and know-how related to human embryonic stem (“hES”) cells; certain biological materials, reagents, laboratory equipment; as well as clinical trial documentation, files and data, primarily related to GRN-OPC1 clinical trials for spinal cord injury and GRN-VAC1 clinical trials for acute myelogenous leukemia. Asterias assumed all obligations related to such assets that would be attributable to periods, events or circumstances after the Asset Contribution closing date, including those related to certain patent interference proceedings and appeals in Federal District Court that have subsequently been settled.
	As consideration for the acquisition of assets from Geron, Asterias issued to Geron 6,537,779 shares of Series A common stock, par value $0.0001 per share (“Series A Shares”), which Geron had agreed to distribute to its stockholders, on a pro rata basis, subject to applicable legal requirements and certain other limitations (the “Series A Distribution”). Asterias agreed to distribute to the holders of its Series A Shares the 8,000,000 BioTime Warrants contributed to Asterias by BioTime (the “BioTime Warrants Distribution”). Geron gave notice to Asterias that the Series A Distribution was completed in August 2014 and during October 2014, Asterias completed the BioTime Warrants Distribution.
	In addition, Asterias agreed to bear certain transaction costs in connection with the Geron asset acquisition. Such transaction costs were allocated to acquisition of assets in the amount of $1,519,904 and issuance of equity in the amount of $541,800.
	The assets contributed to Asterias by Geron did not include workforce or any processes to be applied to the patents, biological materials, and other assets acquired, and therefore did not constitute a business. Accordingly, the acquisition of the Geron assets has been accounted for as an acquisition of assets in accordance with the relevant provisions of Accounting Standards Codification (ASC) 805-50. Total consideration payable by Asterias, including transaction costs, has been allocated to the assets acquired based on relative fair values of those assets as of the date of the transaction, October 1, 2013, in accordance with ASC 820, Fair Value Measurement.
	The assets acquired from Geron and the related consideration were recorded as follows:
	Consideration paid to Geron:
	Asterias Series A shares, net of share issuance costs of $541,800	$	15,121,222
	Obligation to distribute BioTime Warrants		18,276,406
	Transaction and other costs		1,519,904
	Total consideration paid	$	34,917,532
	Assets acquired from Geron (preliminary allocation):
	Patents and other intellectual property rights related to hES cells	$	29,017,009
	Deferred tax liability arising from difference in book versus tax basis on Geron intangible assets acquired		(11,558,243
	IPR&D expensed upon acquisition		17,458,766
	Total assets and in-process research and development acquired	$	34,917,532
	The fair value of the Asterias Series A shares issued was estimated at $2.40 based on the estimated Asterias enterprise value as determined by parties at the time the Asset Contribution Agreement was negotiated and executed by its parties on January 4, 2013, as adjusted for subsequent changes in fair values of assets the parties agreed to contribute.
	The difference between the fair value of assets contributed by Geron and the fair value of consideration issued to Geron was recorded as an additional contribution by Geron, in additional paid-in capital, because the fair value of the assets transferred by Geron was more reliably determined.
	Assets acquired from Geron consist primarily of patents and other intellectual property rights related to hES cells which Asterias intends to license to various parties interested in research, development and commercialization of hES cells technologies, and IPR&D, which includes biological materials, reagents, clinical trial documentation, files and data related primarily to certain clinical trials previously conducted by Geron, which Geron discontinued in November 2011.
	Intangible assets related to IPR&D represent the value of incomplete research and development projects which the company intends to continue. In accordance with the accounting rules in ASC 805, such assets, when acquired in conjunction with acquisition of a business, are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts and are capitalized as an asset. If and when development is complete, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. However, when acquired in conjunction with an acquisition of assets that do not constitute a business (such as the acquisition of assets from Geron), in accordance with the accounting rules in ASC 805-50, such intangible assets related to IPR&D are expensed upon acquisition.
	The values of the acquired assets were estimated at October 1, 2013 based upon a preliminary review of those assets which took into account factors such as the condition of the cells, cell lines and other biological materials being contributed, the stage of development of particular technology and product candidates related to patents, patent applications, and know-how, the intended use of these assets and the priority assigned to the development of product candidates to which those assets relate, and the assessment of the estimated useful lives of patents. The amounts allocated to patents and other intellectual property rights that Asterias intends to license were capitalized as intangible assets and are being amortized over an estimated useful life period of 10 years. The amounts allocated to IPR&D were expensed at the time of acquisition of the related assets in accordance with the requirements of ASC 805-50. The allocation was based on the relative fair value of assets eligible for capitalization and the fair value of assets representing IPR&D before assessing the deferred tax liability arising from the difference in book versus tax basis on Geron intangible assets acquired, which management estimated to be approximately equal. Accordingly, $17,458,766 was capitalized as of December 31, 2013, and $17,458,766 was expensed during the year ended December 31, 2013. The amounts recorded were preliminary as management had not yet completed a detailed assessment and valuation of the acquired assets at the time. During the year ended December 31, 2014, Asterias finalized its assessment of these capitalized intangible assets and recorded an adjustment to reduce the gross intangible cost by $2,157,369 with a corresponding reduction to the accumulated amortization balance of $269,671, resulting in an additional amortization expense of $1,887,698 included in the statements of operations for the year ended December 31, 2014. This adjustment was wholly attributable to finalizing the California income tax rate previously used to compute both the intangible assets and the corresponding deferred income tax liability, recorded at the acquisition date. Accordingly, Asterias simultaneously recorded an adjustment to reduce the related deferred tax liability resulting in the same net amount of $1,887,698 being included in the deferred income tax benefits of $7,375,611 included in the statements of operations for the year ended December 31, 2014. See also Note 5.
	Asterias is also obligated to pay Geron royalties on the sale of products, if any, that are commercialized in reliance upon patents acquired from Geron, at the rate of 4% of net sales.
	Stock and Warrant Purchase Agreement with Romulus
	On January 4, 2013, in connection with entering into the Asset Contribution Agreement, Asterias entered into a Stock and Warrant Purchase Agreement with Romulus Films, Ltd (“Romulus”) pursuant to which Romulus agreed to purchase 2,136,000 Series B Shares and warrants to purchase 350,000 additional Series B Shares for $5,000,000 in cash upon the consummation of the acquisition of assets under the Asset Contribution Agreement. The warrants are exercisable for a period of three years from the date of issuance at an exercise price of $5.00 per share. On October 1, 2013, the shares and warrants were issued in exchange for $5,000,000 in cash.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies [Abstract]
Commitments and Contingencies	15. Commitments and Contingencies
	BioTime had no fixed, non-cancelable contractual obligations as of December 31, 2014, with the exception of office and laboratory facility operating leases.
	BioTime Leases
	BioTime leases office and research laboratory space in Alameda, California. Base monthly rent is $31,675 from December 2014 and will increase by three percent each year. In addition to the base rent, BioTime pays a pro rata share of real property taxes and certain costs associated to the operation and maintenance of the building in which the leased premises are located.
	BioTime also leases an office and research facility located in La Jolla, California. The lease is for a term of one year plus one half month commencing October 15, 2013. It was extended through July 31, 2015. BioTime pays base rent of $4,527 per month, plus operational costs of maintaining the leased premises.
	BioTime also currently pays $5,050 per month for the use of office space in New York City, which is made available to BioTime by one of its directors at his cost for use in conducting meetings and other business affairs.
	Asterias Leases
	BioTime leases an office and research facility located in Menlo Park, California for use by Asterias. The lease is for a term of three years commencing January 7, 2013. Base rent is $31,786 per month, plus real estate taxes and certain costs of maintaining the leased premises.
	On December 30, 2013, Asterias entered into a lease for an office and research facility located in Fremont, California, consisting of an existing building with approximately 44,000 square feet of space. The building will be used by Asterias primarily as a laboratory and production facility that can be used to produce human embryonic stem cells and related products under current good manufacturing procedures (cGMP). Asterias plans to construct certain tenant improvements for its use, which it expects will cost approximately $5.5 million, of which a maximum $4.4 million will be paid by the landlord. The landlord’s obligation to fund the tenant improvements expires on June 30, 2015, 18 months from the date of the lease, with respect to any portion of the allowance not expended by then. Asterias expects to substantially complete construction of the built-to-suit facility during the third quarter of 2015.
	In January 2014, Asterias paid the landlord a $300,000 security deposit and the landlord allowed access and use of the premises beginning in March 2014 to allow for the construction of the tenant improvements. The lease is for a term of 96 months, commencing on October 1, 2014, with two available five-year options to extend the term, upon one year written notice by Asterias. During the first 15 months of the lease term, from October 1, 2014 through December 31, 2015, Asterias will pay monthly base rent of $50,985 representing 22,000 square feet rather than 44,000 square feet provided that Asterias is not in default in performing its obligations under the lease beyond any notice and cure periods. Beginning on January 1, 2016, base rent will increase to $105,142 per month and increase by approximately 3% annually on every October 1 thereafter.
	Total base lease payments under the Fremont lease, including a fixed 3% management fee and 3% escalations, under the lease agreement for the years ending December 31, is shown below:
	Years Ending	Minimum lease
	December 31,	payments
	2015	$	611,820
	2016		1,271,226
	2017		1,309,295
	2018		1,347,364
	2019		1,386,792
	Thereafter		4,033,933
	Total	$	9,960,430
	In addition to monthly base rent, Asterias will pay all real estate taxes, insurance and the cost of maintenance, repair and replacement of the leased premises. During the first 15 months of the lease term, Asterias will pay only 50% of the real estate taxes on the premises provided that Asterias is not in default in performing its obligations under the lease beyond any notice and cure periods. However, if any improvements or alterations to the premises that Asterias constructs or adds are assessed for real property tax purposes at a valuation higher than the valuation of the improvements on the premises on the date it signed the lease, Asterias will pay 100% of the taxes levied on the excess assessed valuation.
	Asterias is considered the owner of the tenant improvements under construction under ASC 840-40-55 as Asterias, among other things, has the primary obligation to pay for construction costs and Asterias will retain exclusive use of the building for its office and research facility requirements after construction is completed. In accordance with this guidance, amounts previously expended by Asterias for construction would continue to be reported as construction in progress in Asterias’ financial statements, and the proceeds received from the landlord will be reported as a liability. Once the property is placed in service, Asterias will depreciate the property and the lease payments allocated to the landlord liability will be accounted for as debt service payments on that liability. As of December 31, 2014, Asterias has incurred approximately $406,000 of construction costs included in construction in progress, of which approximately $378,000 reimbursable by the landlord is included in long term liabilities.
	Asterias was provided access and rights to use the property beginning in March 2014 with “free-rent” until the lease payments commenced on October 1, 2014, as described above. Asterias commenced expensing rent beginning in March 2014 in accordance with ASC 840-20-25-10 and 11, Rent Expense During Construction. Accordingly, during the year ended December 31, 2014, Asterias has expensed approximately $247,000 included in the statements of operations and a deferred rent balance of approximately $94,000 as of December 31, 2014, included in long-term liabilities.
	Asterias also currently pays $3,512 per month for the use of approximately 120 square feet of the office space in New York City that is used to conduct meetings and other business affairs. The lease is for a term of one year commencing July 1, 2014.
	ESI Lease
	ESI had leased approximately 125 square meters of laboratory space in Singapore under a lease that expired on February 28, 2014. Base monthly rent under the Singapore laboratory lease was S$11,000 (approximately US$8,300). In addition to base rent, ESI paid a pro rata share of real property taxes and certain costs related to the operation and maintenance of the building in which the leased premises were located. ESI plans to establish new laboratory facilities in Singapore for manufacturing and distribution of ESI BIO research products in Asia.
	Cell Cure Neurosciences Lease
	Cell Cure Neurosciences leases approximately 290 square meters of office and laboratory space in Hadassah Ein Kerem, in Jerusalem, Israel under a lease that expires on November 30, 2016. Base monthly rent for that facility is approximately ILS 21,930 (approximately US$5,600). In addition to base rent, Cell Cure Neurosciences pays a pro rata share of real property taxes and certain costs related to the operation and maintenance of the building in which the leased premises are located. As of December 31, 2014 Cell Cure Neurosciences has a liability of ILS 328,000 (approximately US$84,000) in improvement costs. This amount is amortized over 2.5 years.
	LifeMap Leases
	LifeMap Sciences leases approximately 320 square meters of office space in Tel Aviv, Israel under a lease expiring on May 31, 2015. Base monthly rent under the lease was originally ILS 21,800 (approximately US$5,600) per month and increased to ILS 25,889 (approximately US$6,600) per month in July 1, 2013 when additional space was added to the leased premises. In addition to base rent, LifeMap Sciences pays a pro rata share of real property taxes and certain costs related to the operation and maintenance of the building in which the leased premises are located. LifeMap Sciences also leases several parking spots.
	LifeMap Sciences leases approximately 120 square meters of office space in Hong Kong under a lease that commenced on December 1, 2013 and expires on November 30, 2015. Base monthly rent under the lease is HK$7,500 (approximately US $970) per month. In addition to base rent, LifeMap pays certain costs related to the operation of the building in which the leased premises are located.
	LifeMap Sciences leases approximately 750 square feet of office space in Marshfield, Massachusetts under a lease that expires on September 30, 2015. Base monthly rent under the lease is approximately $1,170 per month.
	LifeMap Sciences also leases approximately 200 square feet of office space in Hoboken, New Jersey under a lease that expires on February 28, 2018. Base monthly rent under the lease is $1,150 per month.
	LifeMap  Solutions leases approximately 269 square feet of office space in San Jose, California under a lease that expires on November 30, 2015. Base monthly rent under the lease is $1,769 per month
	Rent expenses totaled $2,863,101, $1,599,725, and $1,178,840 for the years ended December 31, 2014, 2013, and 2012, respectively. Remaining minimum annual lease payments under the various operating leases for the year ending after December 31, 2014 are as follows:
	Year Ending	Minimum lease
	December 31,	payments
	2015	$	1,674,583
	2016		1,437,345
	2017		1,323,095
	2018		1,349,664
	2019		1,386,792
	Thereafter		4,033,933
	Total	$	11,205,412

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes [Abstract]
Income Taxes	16. Income Taxes
	The primary components of the net deferred tax liabilities at December 31, 2014 and 2013 were as follows:
	Deferred tax assets/(liabilities):	2014			2013
	Net operating loss carryforwards	$	58,693,000		$	46,711,000
	Research & development and other credits		5,230,000			2,329,000
	Patents and licenses		(8,153,000	)		(11,934,000	)
	Stock options		1,561,000			-
	Other, net		(1,000	)		737,000
	Total		57,330,000			37,843,000
	Valuation allowance		(61,844,000	)		(46,121,000	)
	Net deferred tax liabilities	$	(4,514,000	)	$	(8,278,000	)
	Income taxes differed from the amounts computed by applying the U.S. federal income tax of 34% to pretax losses from operations as a result of the following:
		Year Ended December 31,
		2014			2013			2012
	Computed tax benefit at federal statutory rate		34	%		34	%		34	%
	Research & development and other credits		3	%		-			-
	Permanent differences		(1	%)		(15	%)		(3	%)
	Losses for which no benefit has been recognized		(24	%)		(18	%)		(28	%)
	State tax benefit, net of effect on federal income taxes		3	%		4	%		-
	Foreign rate differential		(1	%)		1	%		(3	%)
			14	%		6	%		0	%
	As of December 31, 2014, BioTime has net operating loss carryforwards of approximately $122,450,000 for federal and $51,206,000 for state tax purposes, which expire in varying amounts between 2015 and 2034. In addition, BioTime has research tax credit carryforwards for federal and state tax purposes of $2,250,000 and $2,250,000, respectively. The federal tax credits expire between 2017 and 2034, while the state tax credits have no expiration date. As of December 31, 2014, BioTime’s subsidiaries have foreign net operating loss carryforwards of approximately $54,207,000 which carry forward indefinitely.
	A deferred income tax benefit of approximately $7,376,000 was recorded for the year ended December 31, 2014, of which approximately $5,155,000 of the benefit was related to federal and $2,221,000 was related to state taxes.  This deferred tax benefit was wholly attributable to BioTime’s majority owned and consolidated subsidiary, Asterias. As disclosed in Note 14, Asterias established deferred tax liabilities primarily related to its acquisition of certain intellectual property. It is more likely than not that the Asterias deferred tax assets are fully realizable since these income tax benefits are expected to be available to offset such Asterias deferred tax liabilities. As BioTime and Asterias file separate U.S. federal tax returns, they may not use each other's tax attributes.  Accordingly, BioTime has established a valuation allowance only pertaining to its deferred tax assets presented in the consolidated balance sheet as of December 31, 2014 and 2013.
	A valuation allowance is provided when it is more likely than not that some portion of the deferred tax assets will not be realized. Except as disclosed above for Asterias, BioTime established a valuation allowance for all periods presented due to the uncertainty of realizing future tax benefits from its net operating loss carryforwards and other deferred tax assets.
	Internal Revenue Code Section 382 places a limitation (“Section 382 Limitation”) on the amount of taxable income that can be offset by net operating loss (“NOL”) carryforwards after a change in control (generally greater than 50% change in ownership within a three-year period) of a loss corporation. California has similar rules. Generally, after a control change, a loss corporation cannot deduct NOL carryforwards in excess of the Section 382 Limitation. Due to these “change in ownership” provisions, utilization of the NOL and tax credit carryforwards may be subject to an annual limitation regarding their utilization against taxable income in future periods.
	BioTime files a U.S. federal income tax return as well as various state and foreign income tax returns. In general, BioTime is no longer subject to tax examination by major taxing authorities for years before 2010. Although the statute is closed for purposes of assessing additional income and tax in these years, the taxing authorities may still make adjustments to the net operating loss and credit carryforwards used in open years. Therefore the statute should be considered open as it relates to the net operating loss and credit carryforwards.
	BioTime's practice is to recognize interest and/or penalties related to income tax matters in tax expense.  As of December 31, 2014, BioTime has no accrued interest and/or penalties.  BioTime may be subject to potential examination by U.S. federal, U.S. states or foreign jurisdiction authorities in the areas of income taxes. These potential examinations may include questioning the timing and amount of deductions, the nexus of income among various tax jurisdictions and compliance with U.S. federal, U.S. state and foreign tax laws. BioTime's management does not expect that the total amount of unrecognized tax benefits will materially change over the next twelve months.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Information [Abstract]
Segment Information	17. Segment Information
	BioTime's executive management team, as a group, represents the entity's chief operating decision makers. To date, BioTime’s executive management team has viewed BioTime’s operations as one segment that includes, the research and development of therapeutic products for oncology, orthopedics, retinal and neurological diseases and disorders, blood and vascular system diseases and disorders, blood plasma volume expansion, diagnostic products for the early detection of cancer, and hydrogel products that may be used in surgery, and products for human embryonic stem cell research. As a result, the financial information disclosed materially represents all of the financial information related to BioTime’s sole operating segment.

Enterprisewide_Disclosures

Enterprise-wide Disclosures	12 Months Ended
	Dec. 31, 2014
Enterprise wide Disclosures [Abstract]
Enterprise-wide Disclosures	18. Enterprise-wide Disclosures
	Geographic Area Information
	Revenues, including license fees, royalties, grant income, and other revenues by geographic area are based on the country of domicile of the licensee or grantor.
				Revenues for the Year ending December 31,
	Geographic Area			2014		2013		2012
	Domestic			$	3,585,729	$	2,106,161	$	2,529,669
	Asia				1,657,475		2,328,175		1,385,658
	Total revenues			$	5,243,204	$	4,434,336	$	3,915,327
	Major Sources of Revenues
	BioTime has two major customers and three major grants comprising significant amounts of total revenues.
	Most of BioTime’s royalty revenues were generated through sales of Hextend® by Hospira in the U.S. and by CJ Health in the Republic of Korea. BioTime also earned license fees from CJ Health. During 2014. Asterias also received royalty revenues from product sales from a non-exclusive license agreement with Stem Cell Technologies, Inc.
	During September 2011, the National Institutes of Health (“NIH”) awarded BioTime a $335,900 research grant (the “2011 NIH Grant”). During 2014 and 2013, BioTime received $116,794 and $111,691, respectively, and recognized as revenues $110,237 and $150,239, respectively, under the 2011 NIH Grant. The grant period commenced on September 30, 2011 and ended on September 29, 2014.
	During 2013, the NIH also awarded BioTime a separate research contract in the amount of $285,423 (the “2013 NIH Contract”). During 2014 and 2013, BioTime received $214,068 and $71,355, respectively, and recognized as revenues $110,237 and $150,239, respectively, under the 2013 NIH Contract. The 2013 NIH Contract period ended on September 4, 2014.
	During 2014, the NIH awarded BioTime three research and development grants.
		·	One grant is for $270,262 (the “2014 NIH Grant #1”). During 2014, BioTime received $71,544 and recognized as revenues $127,584 under the 2014 NIH Grant #1. The 2014 NIH Grant #1 period will end on August 31, 2015.
		·	A second NIH grant is for $292,262 (the “2014 NIH Grant #2”). During 2014, BioTime received $64,899 and recognized as revenues $116,854 under the 2014 NIH Grant #2. The 2014 NIH Grant #2 period will end on August 31, 2015.
		·	The third NIH grant is for $224,911 (the “2014 NIH Grant #3”). During 2014, BioTime received $63,563 and recognized as revenues $87,382 under the 2014 NIH Grant #3. The 2014 NIH Grant #3 period will end on April 30, 2016.
	During 2014 and 2013, grant income also included $2,640,707 and $1,351,735, respectively, from grants awarded to certain BioTime subsidiaries. For 2014, BioTime recognized $1,034,456 of grant income through Asterias under a $14.3 million grant from CIRM and $1,606,251 of grant income through Cell Cure Neurosciences from certain grants, largely from the Office of the Chief Scientist of Israel (“OCS”). For 2013, BioTime recognized $1,333,901 of grant income through Cell Cure Neurosciences from certain grants, largely from OCS, $13,838 through Life Map Sciences, Ltd. from the Klita Institution, and $3,996 through ESI from a grant from the Singapore Ministry of Finance.
	During 2014, BioTime received $1,009,036 and recognized $526,003 (net of $647,071 in royalty and commission fees) in net subscription and advertisement revenues through LifeMap Sciences. During 2013, BioTime received $1,082,077 and recognized $609,314 (net of $707,695 in royalty and commission fees) in net subscription and advertisement revenues through LifeMap Sciences.
	The following table shows the relative portions of BioTime’s royalty and license fee revenues paid by Hospira, CJ Health, and Summit Pharmaceuticals International Corporation (“Summit”) that were recognized during the years ended December 31, 2014, 2013, and 2012, subscription and advertisement revenues, and grant income recognized during the same periods with respect to grants provided by OCS, the NIH and CIRM:
				Revenues for the Year ending December 31,
	Sources of Revenues			2014		2013		2012
	Hospira				3.00%		6.50%		11.00%
	CJ Health				1.00%		1.70%		2.90%
	Summit(1)				-%		20.30%		3.70%
	CIRM				19.70%		-%		26.70%
	NIH				12.50%		5.00%		1.20%
	OCS				31.30%		27.90%		26.00%
	Subscription and Advertising (various customers)				32.50%		38.60%		28.50%
		-1	BioTime recognized the unamortized balance of the Summit license fees during the fourth quarter of 2013 as a result of the termination of its license agreements with Summit.

Selected_Quarterly_Financial_I

Selected Quarterly Financial Information (UNAUDITED)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information (UNAUDITED) [Abstract]
Selected Quarterly Financial Information (UNAUDITED)	19. Selected Quarterly Financial Information (UNAUDITED)
	Year Ended December 31, 2014		First			Second			Third			Fourth
			Quarter			Quarter			Quarter			Quarter
	Revenues, net		$	934,721		$	855,435		$	960,202		$	1,664,563
	Operating expenses			12,072,564			13,917,109			13,097,791			16,804,318
	Loss from operations			(11,137,843	)		(13,061,674	)		(12,137,589	)		(15,139,755	)
	Net loss attributable to BioTime, Inc.(1)			(8,099,014	)		(9,520,190	)		(8,267,925	)		(11,086,716	)
	Basic and diluted net loss per share		$	(0.14	)	$	(0.16	)	$	(0.12	)	$	(0.14	)
	Year Ended December 31, 2013
	Revenues, net		$	431,724		$	1,035,514		$	507,384		$	1,670,063
	Acquired in-process research and development(2)			-			-			-			17,458,766
	Operating expenses			8,811,633			9,151,965			10,709,337			13,504,740
	Loss from operations			(8,379,909	)		(8,116,451	)		(10,201,953	)		(29,293,443	)
	Net loss attributable to BioTime, Inc.(1)			(7,719,263	)		(7,549,765	)		(9,003,168	)		(19,612,314	)
	Basic and diluted net loss per share		$	(0.15	)	$	(0.14	)	$	(0.16	)	$	(0.35	)
		-1	Net of $7,375,611 and $3,280,695 of deferred income tax benefits for 2014 and 2013 respectively.
		-2	Includes IPR&D expenses related to intangible assets acquired by Asterias from Geron under the Asset Contribution Agreement. IPR&D represents the value of incomplete research and development projects which Asterias intends to continue. See Notes 2 and 14.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	20. Subsequent Events
	In January 2015, Asterias received the second payment from CIRM in the amount of $2,269,515.
	In February 2015, Asterias raised approximately $5.5 million in aggregate gross proceeds from the sale of 1,410,255 shares of Series A Common Stock at a price of $3.90 per share through an underwritten public offering and a private placement. Broadwood Partners, L.P., British & American Investment Trust PLC and Pedro Lichtinger purchased an aggregate of 1,025,640 of the shares. Broadwood Partners, L.P. is BioTime’s largest shareholder and one of its directors, Neal C. Bradsher, is President, and one of Asterias’ directors, Richard T. LeBuhn, is Senior Vice President, of Broadwood Capital, Inc., the investment manager of Broadwood Partners, L.P. Pedro Lichtinger is Asterias’ Chief Executive Officer and a member of its Board of Directors. British & American Investment Trust PLC is an affiliate of a stockholder of Asterias and BioTime.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies [Abstract]
Revenue recognition	Revenue recognition – BioTime complies with ASC 605-10 and recognizes revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed or determinable, and collectability is reasonably assured. Grant income and the sale of research products and services are recognized as revenue when earned. Revenues from the sale of research products and services are primarily derived from the sale of hydrogels and stem cell products. Royalty revenues consist of product royalty payments. License fee revenues consist primarily of subscription and advertising revenue from LifeMap Sciences’ online databases which are recognized based upon respective subscription or advertising periods. Other license fees under certain license agreements were recognized during prior periods when earned and reasonably estimable. Royalties earned on product sales are recognized as revenue in the quarter in which the royalty reports are received from the licensee, rather than the quarter in which the sales took place. When BioTime is entitled to receive up-front nonrefundable licensing or similar fees pursuant to agreements under which BioTime has no continuing performance obligations, the fees are recognized as revenues when collection is reasonably assured. When BioTime receives up-front nonrefundable licensing or similar fees pursuant to agreements under which BioTime does have continuing performance obligations, the fees are deferred and amortized ratably over the performance period. If the performance period cannot be reasonably estimated, BioTime amortizes nonrefundable fees over the life of the contract until such time that the performance period can be more reasonably estimated. Milestone payments, if any, related to scientific or technical achievements are recognized in income when the milestone is accomplished if (a) substantive effort was required to achieve the milestone, (b) the amount of the milestone payment appears reasonably commensurate with the effort expended, and (c) collection of the payment is reasonably assured.
Cash and cash equivalents	Cash and cash equivalents – BioTime considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents.
Trade accounts and grants receivable, net	Trade accounts and grants receivable, net – Net trade receivables amounted to approximately $549,300 and $575,900 and grants receivable amounted to approximately $492,600 and $539,300 as of December 31, 2014 and December 31, 2013, respectively. Net trade receivables include allowance for doubtful accounts of approximately $100,500 and $116,800 as of December 31, 2014 and December 31, 2013, respectively for those amounts deemed uncollectible by BioTime. BioTime evaluates the collectability of its receivables based on a variety of factors, including the length of time receivables are past due and significant one-time events and historical experience. An additional reserve for individual accounts will be recorded if BioTime becomes aware of a customer’s inability to meet its financial obligations, such as in the case of bankruptcy filings or deterioration in the customer’s operating results or financial position. If circumstances related to customers change, estimates of the recoverability of receivables would be further adjusted.
Concentrations of credit risk	Concentrations of credit risk – Financial instruments that potentially subject BioTime to significant concentrations of credit risk consist primarily of cash and cash equivalents. BioTime limits the amount of credit exposure of cash balances by maintaining its accounts in high credit quality financial institutions. Cash equivalent deposits with financial institutions may occasionally exceed the limits of insurance on bank deposits; however, BioTime has not experienced any losses on such accounts.
Inventory	Inventory – Inventories are stated at the lower of cost or market. Cost, which includes amounts related to materials, labor, and overhead, is determined in a manner which approximates the first-in, first-out (“FIFO”) method.
Equipment	Equipment, net – Equipment is stated at cost. Equipment is being depreciated using the straight-line method over a period of 36 to 120 months. See Note 4.
Intangible assets	Intangible assets, net – Intangible assets with finite useful lives are amortized over their estimated useful lives and intangible assets with indefinite lives are not amortized but rather are tested at least annually for impairment. Acquired in-process research and development intangible assets are accounted for depending on whether they were acquired as part of an acquisition of a business, or as assets that do not constitute a business. When acquired in conjunction with the acquisition of a business, these assets are considered to be indefinite-lived until the completion or abandonment of the associated research and development efforts and are capitalized as an asset. If and when development is complete, the associated assets would be deemed finite-lived and would then be amortized based on their respective estimated useful lives at that point in time. However, when acquired in conjunction with an acquisition of assets that do not constitute a business (such as the acquisition of assets by Asterias from Geron Corporation), in accordance with the accounting rules in ASC 805-50, such intangible assets related to in-process research and development (“IPR&D”) are expensed upon acquisition. See Note 14.
Treasury stock	Treasury stock – BioTime accounts for BioTime common shares issued to subsidiaries for future potential working capital needs as treasury stock on the consolidated balance sheet. BioTime has the intent and ability to register any unregistered shares to support the marketability of the shares.
Warrants to purchase common stock	Warrants to purchase common stock – BioTime generally accounts for warrants issued in connection with equity financings as a component of equity. None of the warrants issued by BioTime as of December 31, 2014 include a conditional obligation to issue a variable number of shares; nor was there a deemed possibility that BioTime may need to settle the warrants in cash.
Cost of sales	Cost of sales – BioTime accounts for the cost of research products acquired for sale and any royalties paid as a result of any revenues in accordance with the terms of the respective licensing agreements as cost of sales on the consolidated statement of operations and comprehensive loss.
Patent costs	Patent costs – Costs associated with obtaining patents on products or technology developed are expensed as general and administrative expenses when incurred.
Reclassification	Reclassification – Certain prior year amounts have been reclassified to conform to the current year presentation. Trade and grant receivables are now reported separately from prepaid expenses and other current assets.
Research and development	Research and development – Research and development costs are expensed when incurred, and consist principally of salaries, payroll taxes, consulting fees, research and laboratory fees, rent of research facilities, and license fees paid to third parties to acquire patents or licenses to use patents and other technology.
Foreign currency translation gain/(loss) and comprehensive loss	Foreign currency translation gain and comprehensive loss – In countries in which BioTime operates, where the functional currency is other than the U.S. dollar, assets and liabilities are translated using published exchange rates in effect at the consolidated balance sheet date. Revenues and expenses and cash flows are translated using an approximate weighted average exchange rate for the period. Resulting translation adjustments are recorded as a component of accumulated other comprehensive loss on the consolidated balance sheet. For the fiscal years ended December 31, 2014 and 2013, comprehensive loss includes gain of $122,936 and $122,469, respectively which is largely from foreign currency translation. For the fiscal years ended December 31, 2014 and 2013, foreign currency transaction loss amounted to $338,076 and $133,479, respectively.
Income taxes	Income taxes – BioTime accounts for income taxes in accordance with GAAP requirements, which prescribe the use of the asset and liability method, whereby deferred tax asset or liability account balances are calculated at the balance sheet date using current tax laws and rates in effect. Valuation allowances are established when necessary to reduce deferred tax assets when it is more likely than not that a portion or all of the deferred tax assets will not be realized. The FASB guidance also prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more-likely-than-not sustainable upon examination by taxing authorities. Beginning October 1, 2013, Asterias began filing separate U.S. federal income tax returns but effectively BioTime combined Asterias’ tax provision with BioTime’s. For California, Asterias’ activity for 2013 and 2014 will be included in BioTime’s combined tax return. BioTime recognizes accrued interest and penalties related to unrecognized tax benefits as income tax expense, however, no amounts were accrued for the payment of interest and penalties as of December 31, 2014 and December 31, 2013.  BioTime files a U.S. federal income tax return as well as various state and foreign income tax returns. In general, BioTime is no longer subject to tax examination by major taxing authorities for years before 2010.  Although the statute is closed for purposes of assessing additional income and tax in these years, the taxing authorities may still make adjustments to the net operating loss and credti carryforwards used in open years.  Therefore the statute should be considered open as it relates to the net operating loss and credit carryforwards.  Any potential examinations may include questioning the timing and amount of deductions, the nexus of income among various tax jurisdictions and compliance with U.S. federal, state and local and foreign tax laws. Management does not expect that the total amount of unrecognized tax benefits will materially change over the next year.
	A deferred income tax benefit of approximately $7,376,000 was recorded for the year ended December 31, 2014, of which approximately $5,155,000 of the benefit was related to federal and $2,221,000 was related to state taxes. A deferred income tax benefit of approximately $3,280,000 was recorded for the year ended December 31, 2013, of which approximately $2,800,000 was related to federal and $480,000 was related to state taxes. As disclosed in Note 14, Asterias established deferred tax liabilities primarily related to its acquisition of certain intellectual property. It is more likely than not that the Asterias deferred tax assets are fully realizable since these income tax benefits are expected to be available to offset such Asterias deferred tax liabilities.
	In June 2014, Asterias' sale of BioTime shares resulted in a taxable gain of approximately $10.3 million and a tax payable of $3.6 million. Asterias received the BioTime shares from BioTime as part of their consideration under the Asset Contribution Agreement, a tax free transaction. This payable, however, is expected to be fully offset by available net operating losses thus, resulting in no cash income taxes due from that sale.  This transaction was treated as a deemed distribution by Asterias and recorded against equity.
Stock-based compensation	Stock-based compensation – BioTime follows accounting standards governing share-based payments, which require the measurement and recognition of compensation expense for all share-based payment awards made to directors and employees, including employee stock options, based on estimated fair values. Consistent with FASB guidelines, BioTime utilizes the Black-Scholes Merton option pricing model for valuing share-based payment awards. BioTime's determination of fair value of share-based payment awards on the date of grant using that option-pricing model is affected by BioTime's stock price as well as by assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, BioTime's expected stock price volatility over the term of the awards, and actual and projected employee stock option exercise behaviors. The expected term of options granted is derived from historical data on employee exercises and post-vesting employment termination behavior. The risk-free rate is based on the U.S. Treasury rates in effect during the corresponding period of grant. Although the fair value of employee stock options is determined in accordance with recent FASB guidance, changes in the subjective assumptions can materially affect the estimated value.
Impairment of long-lived assets	Impairment of long-lived assets – BioTime’s long-lived assets, including intangible assets, are reviewed annually for impairment and whenever events or changes in circumstances indicate that the carrying amount of an asset may not be fully recoverable. If an impairment indicator is present, BioTime will evaluate recoverability by a comparison of the carrying amount of the assets to future undiscounted net cash flows expected to be generated by the assets. If the assets are impaired, the impairment recognized is measured by the amount by which the carrying amount exceeds the estimated fair value of the assets.
Deferred license and consulting fees	Deferred license and consulting fees – Deferred license and consulting fees consist of the value of warrants issued to third parties for services, and deferred license fees paid to acquire rights to use the proprietary technologies of third parties. The value of the warrants is being amortized over the period the services are being provided, and the license fees are being amortized over the estimated useful lives of the licensed technologies or licensed research products. BioTime is applying a 10 year estimated useful life to the technologies and products that it is currently licensing. The estimation of the useful life any technology or product involves a significant degree of inherent uncertainty, since the outcome of research and development or the commercial life of a new product cannot be known with certainty at the time that the right to use the technology or product is acquired. BioTime will review the continued appropriateness of the 10 year estimated useful life for impairments that might occur earlier than the original expected useful lives. See Note 6.
Loss per share	Loss per share – Basic net loss per share attributable to common shareholders is computed by dividing net loss attributable to the common shareholders of BioTime by the weighted-average number of common stock outstanding for the period. Diluted net loss per share reflects the weighted-average number of common stock outstanding plus the potential effect of dilutive securities or contracts which are convertible to common shares, such as options and warrants (using the treasury stock method) and shares issuable in future periods. Diluted net loss per share for years ended December 31, 2014, 2013, and 2012 excludes any effect from 4,893,942 treasury shares, 3,974,326 options and 9,194,679 warrants, 10,697,715 treasury shares, 4,567,135 options and 9,751,615 warrants, and 1,800,109 treasury shares, 3,681,301 options and 556,613 warrants, respectively because their inclusion would be antidilutive.
Fair value of financial instruments	Fair value of financial instruments – The fair value of BioTime’s assets and liabilities, which qualify as financial instruments under FASB guidance regarding disclosures about fair value of financial instruments, approximate the carrying amounts presented in the accompanying  consolidated balance sheets.
Effect of recently issued and recently adopted accounting pronouncements	Effect of recently issued and recently adopted accounting pronouncements – The following accounting standards, which are not yet effective, are presently being evaluated by BioTime to determine the impact that they might have on its consolidated financial statements.
	In May 2014, the FASB issued Accounting Standards Update (“ASU”) No. 2014-09 “Revenue from Contracts with Customers” (Topic 606). The guidance of this update effects any entity that either issues contracts with customers or transfers goods or services or enters into contracts for the transfer of non-financial assets. The core principal of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in the amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. To achieve those core principals, the ASU specifies steps that the entity should apply for revenue recognition. The guidance also specifies the accounting for some costs to obtain or fulfill the contract with customer and disclosure requirements to enable users of financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. For a public entity, ASU No. 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. BioTime is currently evaluating the impact of the adoption of the ASU on its consolidated financial statements.
	In June 2014, the FASB issued ASU No. 2014-12 “Compensation – Stock Compensation” (Topic 718). The ASU provides guidance for accounting for share-based payments when the terms of an award provide that a performance target could be achieved after the requisite service period. That is the case when an employee is eligible to retire or otherwise terminate employment before the end of the period in which a performance target (for example, profitability target) could be achieved and still be eligible to vest in the award if and when the performance target is achieved. The ASU requires a performance target that effects vesting and that could be achieved after the requisite service period be treated as a performance condition. Compensation cost should be recognized in the period in which it becomes probable that such performance condition would be achieved and should represent the compensation cost attributable to the periods for which the requisite service has already been rendered. For public business entities, the ASU is effective for annual reporting periods beginning after December 15, 2015, and interim periods therein. Early application is permitted. BioTime is in the process of evaluating the impact of adoption of the ASU on its consolidated financial statements.
	In August 2014, the FASB issued ASU No. 2014-15 “Presentation of Financial Statements – Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern” requiring management to evaluate on a regular basis whether any conditions or events have arisen that could raise substantial doubt about the entity’s ability to continue as a going concern. The guidance 1) provides a definition for the term “substantial doubt,” 2) requires an evaluation every reporting period, interim periods included, 3) provides principles for considering the mitigating effect of management’s plans to alleviate the substantial doubt, 4) requires certain disclosures if the substantial doubt is alleviated as a result of management’s plans, 5) requires an express statement, as well as other disclosures, if the substantial doubt is not alleviated, and 6) requires an assessment period of one year from the date the financial statements are issued. The standard is effective for BioTime’s reporting year ending December 31, 2016, and interim periods thereafter. Early adoption is permitted. BioTime does not expect the adoption of this guidance to have a material impact on its financial statements.

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation and Liquidity (Tables)	12 Months Ended
	Dec. 31, 2014
Organization and Basis of Presentation and Liquidity [Abstract]
BioTime's ownership of outstanding shares of its subsidiaries	The following table reflects BioTime’s ownership, directly or through one or more subsidiaries, of the outstanding shares of its subsidiaries as of December 31, 2014.
			BioTime
	Subsidiary	Field of Business	Ownership	Country
	Asterias Biotherapeutics, Inc.	Research, development and commercialization of human therapeutic products from stem cells, focused initially in the fields of neurology and oncology	70.6%(1)	USA
	BioTime Asia, Limited	Stem cell products for research	81%	Hong Kong
	Cell Cure Neurosciences Ltd.	Age-related macular degeneration	62.5%(2)	Israel
		Multiple sclerosis
		Parkinson’s disease
	ES Cell International Pte Ltd	Stem cell products for research, including clinical grade cell lines produced under cGMP	100%	Singapore
	LifeMap Sciences, Inc.	Biomedical, gene, disease, and stem cell databases and tools	74.50%	USA
	LifeMap Sciences, Ltd.	Biomedical, gene, disease, and stem cell databases and tools	-3	Israel
	LifeMap Solutions, Inc.	Mobile health software	-3	USA
	OncoCyte Corporation	Cancer diagnostics	75.30%	USA
	OrthoCyte Corporation	Orthopedic diseases, including chronic back pain and osteoarthritis	100%(4)	USA
	ReCyte Therapeutics, Inc.	Vascular disorders, including cardiovascular-related diseases, ischemic conditions, vascular injuries	94.80%	USA
		Stem cell-derived endothelial and cardiovascular related progenitor cells that have applications in research, drug testing, and therapeutics
		-1	During February 2015, Asterias sold 1,410,255 shares of its Series A Common Stock to investors, which reduced BioTime’s percentage ownership of Asterias to 67.5%.
		-2	Includes shares owned by BioTime, Asterias, and ESI.
		-3	LifeMap Sciences, Ltd. and LifeMap Solutions, Inc. are wholly-owned subsidiaries of LifeMap Sciences, Inc.
		-4	Includes shares owned by BioTime and Asterias.

Equipment_Tables

Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Equipment [Abstract]
Equipment, furniture and fixtures	At December 31, 2014 and 2013, equipment, furniture and fixtures, and construction in progress were comprised of the following:
		2014			2013
	Equipment, furniture and fixtures	$	4,870,516		$	4,431,586
	Construction in progress		405,730			-
	Accumulated depreciation		(2,418,400	)		(1,433,853	)
	Equipment net of accumulated depreciation	$	2,857,846		$	2,997,733

Intangible_assets_Tables

Intangible assets (Tables)	12 Months Ended
	Dec. 31, 2014
Intangible assets [Abstract]
Intangible assets	At December 31, 2014 and 2013, intangible assets and accumulated intangible assets were comprised of the following:
		2014			2013
	Intangible assets	$	52,562,549		$	54,719,918
	Accumulated amortization		(13,714,153	)		(8,511,833	)
	Intangible assets, net	$	38,848,396		$	46,208,085
Intangible assets future amortization expense	Amortization of intangible assets for periods subsequent to December 31, 2014 is as follows:
	Year Ended	Amortization
	December 31,	Expense
	2015	$	5,256,255
	2016		5,256,255
	2017		5,256,255
	2018		5,256,255
	2019		5,256,255
	Thereafter		12,567,121
	Total	$	38,848,396

Royalty_Obligation_and_Deferre1

Royalty Obligation and Deferred License Fees (Tables)	12 Months Ended
	Dec. 31, 2014
Royalty Obligation and Deferred License Fees [Abstract]
Amortization of deferred license fees	As of December 31, 2014, amortization of deferred license fees was as follows:
	Year Ended	Deferred License
	December 31,	Fees
	2015	$	109,500
	2016		109,500
	2017		109,500
	2018		73,667
	2019		24,083
	Thereafter		20,083
	Total	$	446,333

Accounts_Payable_and_Accrued_L1

Accounts Payable and Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Accounts Payable and Accrued Liabilities [Abstract]
Accounts payable and accrued liabilities	At December 31, 2014 and 2013, accounts payable and accrued liabilities consist of the following:
		December 31,
		2014		2013
	Accounts payable	$	2,296,645	$	3,434,748
	Accrued expenses		3,125,023		2,296,146
	Accrued bonuses		964,189		600,000
	Other current liabilities		417,316		391,730
	Total	$	6,803,173	$	6,722,624

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Shareholders' Equity [Abstract]
Activity related to warrants	BioTime has issued warrants to purchase its common shares. Activity related to warrants in 2014 and 2013 is presented in the table below:
		Number of			Per share			Weighted Average
		Warrants			exercise			Exercise
					price			Price
	Outstanding, January 1, 2013		556,613		$	10		$	10
	Issued in 2013		9,195,002			5			5
	Outstanding, December 31, 2013		9,751,615		$	5.00 – 10.00		$	5.29
	Exercised in 2014		(556,613	)		10			10
	Retired in 2014		(313	)		5			5
	Exercised in 2014		(10	)		5			5
	Outstanding, December 31, 2014		9,194,679		$	5		$	5
Summary of stock option activity for subsidiaries	A summary of all option activity under the subsidiary option plans (See Note 10) for the years ended December 31, 2014 and 2013 is as follows:
		Options			Number of			Weighted
		Available for			Options			Average
		Grant			Outstanding			Exercise
								Price
	1-Jan-13		6,041,556			7,816,413		$	0.93
	Increase option pool		500,000			-			-
	Granted in 2013		(4,434,995	)		4,434,995			2.11
	Expired/Forfeited/Exercised in 2013		785,000			(785,000	)		1.95
	31-Dec-13		2,891,561			11,466,408		$	1.32
	Granted in 2014		(1,603,167	)		1,603,167			6.59
	Expired/Forfeited/Exercised in 2014		1,368,904			(1,368,904	)		2.28
	31-Dec-14		2,657,298			11,700,671		$	1.98

Stock_Option_Plans_Tables

Stock Option Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Stock Option Plans [Abstract]
Allocation of stock based compensation expense	The following table summarizes stock-based compensation expense related to employee and director stock options awards for the years ended December 31, 2014, 2013, and 2012, which was allocated as follows:
		Year Ended December 31,
	All stock-based compensation expense:	2014					2013					2012
	Research and Development	$	1,309,703				$	829,938				$	815,052
	General and Administrative		3,145,717					2,214,836					1,028,910
	All stock-based compensation expense included in expenses	$	4,455,420				$	3,044,774				$	1,843,962
Schedule of weighted average assumptions to calculate fair value of stock options	The weighted-average estimated fair value of stock options granted during the years ended December 31, 2014 and 2013 was $3.43 and $4.13 per share respectively, using the Black-Scholes Merton model with the following weighted-average assumptions:
		Year Ended
		December 31,
		2014				2013
	Expected life (in years)		6.67				6.68
	Risk-free interest rates		2.19	%			1.51	%
	Volatility		83.2	%			95.22	%
	Dividend yield		0	%			0	%
Summary of stock option activity		Options					Number of					Weighted
		Available for					Options					Average
		Grant					Outstanding					Exercise
												Price
	1-Jan-13		3,745,000					3,681,301				$	1.96
	Granted under 2012 Plan		(1,585,000	)				1,585,000					4.13
	Exercised		-					(20,000	)				2.3
	Forfeited/expired under 2002 Plan		-					(524,166	)				4.01
	Forfeited/expired under 2012 Plan		155,000					(155,000	)				4.18
	31-Dec-13		2,315,000					4,567,135				$	2.71
	Granted under 2012 Plan		(2,170,000	)				2,170,000					3.54
	Exercised		-					(2,060,400	)				0.58
	Forfeited/expired under 2002 Plan		-					(179,491	)				4.32
	Forfeited/expired under 2012 Plan		522,918					(522,918	)				3.72
	31-Dec-14		667,918					3,974,326				$	4.04
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional information regarding options outstanding	Additional information regarding options outstanding as of December 31, 2014 is as follows:
					Options Outstanding									Options Exercisable
	Range of Exercise		Number			Weighted Avg.				Weighted Avg.						Number	Weighted Avg.
	Prices		Outstanding			Remaining				Exercise Price						Exercisable	Exercise Price
						Contractual Life
						(years)
	2.52-8.58		3,974,326				5.57			$	4.04					1,716,099	$	4.48
	$2.52-8.58		3,974,326				5.57			$	4.04					1,716,099	$	4.48
OncoCyte, OrthoCyte, ReCyte Therapeutics, Cell Cure Neurosciences, LifeMap and BioTime Asia [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional information regarding options outstanding	During 2013, BioTime’s subsidiary, LifeMap Solutions adopted a stock option plan that has substantially the same operative provisions as the BioTime 2002 Stock Option Plan. The LifeMap Sciences stock option plan authorized the sale of up to 18,667 shares of its common stock through the exercise of stock options or under restricted stock purchase agreements.
					Subsidiary Options Outstanding									Options Exercisable
	Range of Exercise	Number				Weighted Avg.				Weighted Avg.					Number		Weighted Avg.
	Prices	Outstanding				Remaining				Exercise Price					Exercisable		Exercise Price
						Contractual Life (years)
	$0.003-$0.75	5,256,226					4.96			$	0.36				5,091,506		$	0.37
	1.00-1.75	1,986,772					4.87				1.58				1,157,886			1.5
	2.05-2.34	4,361,666					5.53				2.26				2,066,146			2.18
	3.88-6.25	75,000					0.12				0.105				2,708			0.01
	27.00-42.02	7,840					5.8				37.35				7,840			37.35
	500	13,167					0.04				3.31				1,993			0.86
	$0.003-$500.00	11,700,671					5.17			$	1.9				8,328,079		$	1.13

Asset_Contribution_Agreement_T

Asset Contribution Agreement (Tables)	12 Months Ended
	Dec. 31, 2014
Asset Contribution Agreement [Abstract]
Assets Transferred by BioTime and Related Consideration	The assets transferred by BioTime and the related consideration paid were recorded as follows:
	Consideration transferred to BioTime:
	Asterias Series B shares	$	52,164,568
	Warrants to purchase Asterias Series B shares		2,012,481
	Excess of contributed assets’ value over consideration		4,800,063
	Total consideration issued	$	58,977,112
	Assets transferred by BioTime:
	BioTime common shares, at fair value	$	34,985,163
	BioTime Warrants, at fair value		18,276,406
	Cancellation of outstanding obligation to BioTime		5,000,000
	Investment in affiliates, at cost		415,543
	Geron asset acquisition related transaction costs paid by BioTime		300,000
	Total assets transferred	$	58,977,112
Assets Acquired from Geron and Related Consideration	The assets acquired from Geron and the related consideration were recorded as follows:
	Consideration paid to Geron:
	Asterias Series A shares, net of share issuance costs of $541,800	$	15,121,222
	Obligation to distribute BioTime Warrants		18,276,406
	Transaction and other costs		1,519,904
	Total consideration paid	$	34,917,532
	Assets acquired from Geron (preliminary allocation):
	Patents and other intellectual property rights related to hES cells	$	29,017,009
	Deferred tax liability arising from difference in book versus tax basis on Geron intangible assets acquired		(11,558,243
	IPR&D expensed upon acquisition		17,458,766
	Total assets and in-process research and development acquired	$	34,917,532

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies [Abstract]
Base lease payments under Fremont lease	Total base lease payments under the Fremont lease, including a fixed 3% management fee and 3% escalations, under the lease agreement for the years ending December 31, is shown below:
	Years Ending	Minimum lease
	December 31,	payments
	2015	$	611,820
	2016		1,271,226
	2017		1,309,295
	2018		1,347,364
	2019		1,386,792
	Thereafter		4,033,933
	Total	$	9,960,430
Future minimum operating lease payments	Remaining minimum annual lease payments under the various operating leases for the year ending after December 31, 2014 are as follows:
	Year Ending	Minimum lease
	December 31,	payments
	2015	$	1,674,583
	2016		1,437,345
	2017		1,323,095
	2018		1,349,664
	2019		1,386,792
	Thereafter		4,033,933
	Total	$	11,205,412

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes [Abstract]
Components of net deferred tax assets	The primary components of the net deferred tax liabilities at December 31, 2014 and 2013 were as follows:
	Deferred tax assets/(liabilities):	2014			2013
	Net operating loss carryforwards	$	58,693,000		$	46,711,000
	Research & development and other credits		5,230,000			2,329,000
	Patents and licenses		(8,153,000	)		(11,934,000	)
	Stock options		1,561,000			-
	Other, net		(1,000	)		737,000
	Total		57,330,000			37,843,000
	Valuation allowance		(61,844,000	)		(46,121,000	)
	Net deferred tax liabilities	$	(4,514,000	)	$	(8,278,000	)
Income tax rate reconciliation	Income taxes differed from the amounts computed by applying the U.S. federal income tax of 34% to pretax losses from operations as a result of the following:
		Year Ended December 31,
		2014			2013			2012
	Computed tax benefit at federal statutory rate		34	%		34	%		34	%
	Research & development and other credits		3	%		-			-
	Permanent differences		(1	%)		(15	%)		(3	%)
	Losses for which no benefit has been recognized		(24	%)		(18	%)		(28	%)
	State tax benefit, net of effect on federal income taxes		3	%		4	%		-
	Foreign rate differential		(1	%)		1	%		(3	%)
			14	%		6	%		0	%

Enterprisewide_Disclosures_Tab

Enterprise-wide Disclosures (Tables)	12 Months Ended
	Dec. 31, 2014
Enterprise wide Disclosures [Abstract]
Geographic Area Information	Revenues, including license fees, royalties, grant income, and other revenues by geographic area are based on the country of domicile of the licensee or grantor.
				Revenues for the Year ending December 31,
	Geographic Area			2014		2013		2012
	Domestic			$	3,585,729	$	2,106,161	$	2,529,669
	Asia				1,657,475		2,328,175		1,385,658
	Total revenues			$	5,243,204	$	4,434,336	$	3,915,327
Sources of Revenues	The following table shows the relative portions of BioTime’s royalty and license fee revenues paid by Hospira, CJ Health, and Summit Pharmaceuticals International Corporation (“Summit”) that were recognized during the years ended December 31, 2014, 2013, and 2012, subscription and advertisement revenues, and grant income recognized during the same periods with respect to grants provided by OCS, the NIH and CIRM:
				Revenues for the Year ending December 31,
	Sources of Revenues			2014		2013		2012
	Hospira				3.00%		6.50%		11.00%
	CJ Health				1.00%		1.70%		2.90%
	Summit(1)				-%		20.30%		3.70%
	CIRM				19.70%		-%		26.70%
	NIH				12.50%		5.00%		1.20%
	OCS				31.30%		27.90%		26.00%
	Subscription and Advertising (various customers)				32.50%		38.60%		28.50%
		-1	BioTime recognized the unamortized balance of the Summit license fees during the fourth quarter of 2013 as a result of the termination of its license agreements with Summit.

Selected_Quarterly_Financial_I1

Selected Quarterly Financial Information (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Information (UNAUDITED) [Abstract]
Selected Quarterly Financial Information	19. Selected Quarterly Financial Information (UNAUDITED)
	Year Ended December 31, 2014		First			Second			Third			Fourth
			Quarter			Quarter			Quarter			Quarter
	Revenues, net		$	934,721		$	855,435		$	960,202		$	1,664,563
	Operating expenses			12,072,564			13,917,109			13,097,791			16,804,318
	Loss from operations			(11,137,843	)		(13,061,674	)		(12,137,589	)		(15,139,755	)
	Net loss attributable to BioTime, Inc.(1)			(8,099,014	)		(9,520,190	)		(8,267,925	)		(11,086,716	)
	Basic and diluted net loss per share		$	(0.14	)	$	(0.16	)	$	(0.12	)	$	(0.14	)
	Year Ended December 31, 2013
	Revenues, net		$	431,724		$	1,035,514		$	507,384		$	1,670,063
	Acquired in-process research and development(2)			-			-			-			17,458,766
	Operating expenses			8,811,633			9,151,965			10,709,337			13,504,740
	Loss from operations			(8,379,909	)		(8,116,451	)		(10,201,953	)		(29,293,443	)
	Net loss attributable to BioTime, Inc.(1)			(7,719,263	)		(7,549,765	)		(9,003,168	)		(19,612,314	)
	Basic and diluted net loss per share		$	(0.15	)	$	(0.14	)	$	(0.16	)	$	(0.35	)
		-1	Net of $7,375,611 and $3,280,695 of deferred income tax benefits for 2014 and 2013 respectively.
		-2	Includes IPR&D expenses related to intangible assets acquired by Asterias from Geron under the Asset Contribution Agreement. IPR&D represents the value of incomplete research and development projects which Asterias intends to continue. See Notes 2 and 14.

Organization_and_Basis_of_Pres2

Organization and Basis of Presentation and Liquidity (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 28, 2015
Noncontrolling Interest [Line Items]
Common Stock, Shares, Issued	83,121,698		67,412,139
Accumulated deficit	($182,190,207)		($145,778,547)
Shareholders' equity	62,722,765		42,262,321	24,294,373	41,458,181
Cash and cash equivalents	29,486,909		5,495,478	4,349,967	22,211,897
Parent [Member]
Noncontrolling Interest [Line Items]
Accumulated deficit	-182,190,207
Working capital	25,275,290
Shareholders' equity	62,722,765
Cash and cash equivalents	$29,486,909
Asterias Biotherapeutics, Inc. [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	70.60%	[1]				67.50%
Asterias Biotherapeutics, Inc. [Member] | Series A Common Stock [Member]
Noncontrolling Interest [Line Items]
Common Stock, Shares, Issued						1,410,255
BioTime Asia, Limited [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	81.00%
Cell Cure Neurosciences, Ltd. [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	62.50%	[2]
ES Cell International Pte., Ltd. [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	100.00%
LifeMap Sciences, Inc. [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	74.50%
LifeMap Sciences, Ltd. [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	0.00%	[3]
LifeMap Solutions, Inc [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	0.00%	[3]
OncoCyte Corporation [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	75.30%
OrthoCyte Corporation [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	100.00%	[4]
ReCyte Therapeutics, Inc. [Member]
Noncontrolling Interest [Line Items]
BioTime Ownership (in hundredths)	94.80%
[1]	During February 2015, Asterias sold 1,410,255 shares of its Series A Common Stock to investors, which reduced our percentage ownership of Asterias to 67.5%.
[2]	Includes shares owned by BioTime, Asterias, and ESI.
[3]	LifeMap Sciences, Ltd. and LifeMap Solutions, Inc. are wholly-owned subsidiaries of LifeMap Sciences, Inc.
[4]	Includes shares owned by BioTime and Asterias.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014
Summary of Significant Accounting Policies [Abstract]
Trade receivable	$549,300	$575,900
Grants receivable	492,600	539,300
Allowance for doubtful accounts	100,500	116,800
Property, Plant and Equipment [Line Items]
Foreign currency gain (loss) included in comprehensive loss	122,936	122,469
Foreign currency transaction gain (loss)	338,076	133,479
Income Taxes [Abstract]
Deferred income tax benefit	-7,375,611	-3,280,695	0
Deferred income tax benefit, federal	-5,155,000	-2,800,000
Deferred income tax benefit, state taxes	-2,221,000	-480,000
Taxable gain on sale of subsidiary shares				10,300,000
Tax payable on sale of subsidiary shares				$3,600,000
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life	10 years
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted loss per share (in shares)	3,974,326	4,567,135	3,681,301
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted loss per share (in shares)	9,194,679	9,751,615
Treasury Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted loss per share (in shares)	4,893,942	10,697,715	1,800,109
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset, useful life	10 years
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Equipment useful life	36 months
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Equipment useful life	120 months

Inventory_Details

Inventory (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Inventory [Abstract]
Inventory of finished products on-site	$253,227	$165,771
Inventory held by third party on consignment	$12,795	$12,923

Equipment_Details

Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014
Equipment, furniture and fixtures [Abstract]
Equipment, furniture and fixtures	$4,870,516	$4,431,586
Construction in progress	405,730	0
Accumulated depreciation	-2,418,400	-1,433,853
Equipment net of accumulated depreciation	2,857,846	2,997,733
Equipment, furniture, and fixtures included in capital lease borrowings				115,000
Leasehold improvements for Asterias' facility	405,730
Depreciation expense	1,050,651	656,759	386,457
Increase in accumulated depreciation	984,547
Tenant Improvement Allowance Under Lease Agreement	$4,400,000

Intangible_assets_Details

Intangible assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Intangible assets, net [Abstract]
Intangible assets	$52,562,549	$54,719,918
Accumulated amortization	-13,714,153	-8,511,833
Intangible assets, net	38,848,396	46,208,085
Intangible assets, useful life	10 years
Amortization of intangible assets	7,359,690	3,295,716	2,446,975
Adjustments to intangible assets due to deferred tax liability	2,157,369
Accumulated amortization of intangible assets	269,671
Amortization expense for intangible assets	1,887,698
Intangible assets future amortization expense [Abstract]
2015	5,256,255
2016	5,256,255
2017	5,256,255
2018	5,256,255
2019	5,256,255
Thereafter	12,567,121
Intangible assets, net	$38,848,396	$46,208,085

Royalty_Obligation_and_Deferre2

Royalty Obligation and Deferred License Fees (Details)

12 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

USD ($)

USD ($)

USD ($)

WARF [Member]

WARF [Member]

WARF [Member]

WARF [Member]

Sanford-Burnham Medical Research Institute [Member]

Sanford-Burnham Medical Research Institute [Member]

Sanford-Burnham Medical Research Institute [Member]

Hadasit Medical Research Services and Development Ltd [Member]

Hadasit Medical Research Services and Development Ltd [Member]

Hadasit Medical Research Services and Development Ltd [Member]

Hadasit Medical Research Services and Development Ltd [Member]

Hadasit Medical Research Services and Development Ltd (Clinical trial phase I) [Member]

Hadasit Medical Research Services and Development Ltd (Clinical trial phase II) [Member]

Hadasit Medical Research Services and Development Ltd (Clinical trial phase III) [Member]

University of Utah License [Member]

University of Utah License [Member]

University of Utah License, Milestone I [Member]

Asterias License from the University of California [Member]

Asterias Sublicenes from Geron [Member]

Ocata Therapeutics, Inc. [Member]

Ocata Therapeutics, Inc. [Member]

Ocata Technology [Member]

Ocata Technology [Member]

Ocata Technology, With Kirin Sublicense II [Member]

Ocata Technology, With Kirin Sublicense II [Member]

USD ($)

USD ($)

Minimum [Member]

Maximum [Member]

Pharmaceutical Products [Member]

Research Use Products [Member]

USD ($)

ILS

Minimum [Member]

Maximum [Member]

USD ($)

USD ($)

USD ($)

USD ($)

Minimum [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Finite-Lived Intangible Assets [Line Items]

Intangible assets, useful life

10 years

20 years

20 years

Royalty rate on sale of products and services (in hundredths)

2.00%

4.00%

4.00%

10.00%

5.00%

5.00%

3.00%

1.00%

1.00%

8.00%

5.00%

3.50%

Licensing fees paid

$295,000

$65,000

$250,000

$200,000

$50,000

Amortization of deferred license, royalty and subscription revenues

-579

-915,028

-211,065

151,083

121,583

159,917

134,917

126,667

106,667

31,667

26,667

Maximum royalty payments

1,000,000

600,000

Fees for sublicense (in hundredths)

20.00%

10.00%

30.00%

30.00%

7.50%

20.00%

20.00%

Reduction in royalties payable, percentage (in hundredths)

50.00%

Portion of fees for filing, prosecuting, and maintaining patent protection to be reimbursed by subsidiary (in hundredths)

25.00%

Payment for patent expense

63,860

249,058

Annual minimum royalty due

100,000

5,000

50,000

Payments for attaining milestone

250,000

250,000

1,000,000

5,000

2,500

225,000

Minimum royalty amount in 2015 and thereafter

30,000

Number of other licensees that triggers reduction in payments for attaining milestone

2

Number of licensed patents issued that trigger payments to licensor

5

Minimum royalty amount in 2014

2,500

Maximum reduction in royalty payments (in hundredths)

50.00%

Period of notice for termination of the agreement

60 days

90 days

Annual license maintenance fee

10,000

Amortization of deferred license fees [Abstract]

2015

109,500

2016

109,500

2017

109,500

2018

73,667

2019

24,083

Thereafter

20,083

Total

446,333

Prepaid expenses in other current assets

109,500

Deferred license and consulting fees in noncurrent assts

$336,833

Accounts_Payable_and_Accrued_L2

Accounts Payable and Accrued Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Accounts Payable and Accrued Liabilities [Abstract]
Accounts payable	$2,296,645	$3,434,748
Accrued expenses	3,125,023	2,296,146
Accrued bonuses	964,189	600,000
Other current liabilities	417,316	391,730
Total	$6,803,173	$6,722,624

Related_Party_Transactions_and1

Related Party Transactions and Related Party Convertible Debt(Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	sqft
Related Party Transaction [Line Items]
Rent per month	$5,050
Area of office space (in square feet)	900
Number of warrants issued (in shares)		8,000,000
Principal and accumulated interest	470,856	0	0
Proceeds from issuance of common shares	44,150,069	25,938,558	1,131,279
BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	96,150
Shares sold (in shares)	9,431,398
Proceeds from shares sold	29,425,962
Stock price (in dollars per share)	$3.12
Number of directors	3
Asterias Biotherapeutics [Member]
Related Party Transaction [Line Items]
Proceeds from issuance of common shares	468,000
Asterias Biotherapeutics [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares sold (in shares)	5,000,000
Number of investors	2
Proceeds from sale of BioTime stock	12,500,000
Asterias Biotherapeutics [Member] | Astericas Series B Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	5,000,000
Number of shares sold (in shares)	200,000
Broadwood Partners, LP [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	4,040,523
Broadwood Partners, LP [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	1,000,000
Broadwood Partners, LP [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Number of warrants issued (in shares)	1,000,000
George Karfunkel [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	4,000,000
Ownership percentage (in hundredths)	5.00%
George Karfunkel [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Number of warrants issued (in shares)	4,000,000
Cell Cure Neurosciences, Ltd. [Member]
Related Party Transaction [Line Items]
Number of Cell Cure Neurosciences investors	2
Principal and accumulated interest	469,247
Stated interest rate (in hundredths)	3.00%
Conversion price (in dollars per share)	$20
Estimated fair market value (in dollars per share)	$41
Accrued interest is payable period	3 years
Effective annual interest rate (in hundredths)	23.00%
Carrying value of convertible notes	60,237
Amount of convertible note	472,834
Unamortized debt discount	$412,597

Shareholders_Equity_Warrants_a

Shareholders' Equity, Warrants and Options (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Per share exercise price [Abstract]
Outstanding Ending Balance (in dollars per share)	$5
OncoCyte, OrthoCyte, ReCyte Therapeutics, Cell Cure Neurosciences, LifeMap and BioTime Asia [Member]
Options Available for Grant [Rollforward]
Beginning of the period (in shares)	2,891,561	6,041,556
Increase option pool (in shares)		500,000
Granted (in shares)	-1,603,167	-4,434,995
Expired/Forfeited/Exercised	1,368,904	785,000
End of the period (in shares)	2,657,298	2,891,561
Number of Options Outstanding [Rollforward]
Outstanding, beginning of the period (in shares)	11,466,408	7,816,413
Increase option pool (in shares)		0
Granted (in shares)	1,603,167	4,434,995
Expired/Forfeited/Exercised (in shares)	-1,368,904	-785,000
Outstanding, end of the period (in shares)	11,700,671	11,466,408
Weighted Average Exercise Price [Rollforward]
Outstanding, beginning of the period (in dollars per share)	$1.32	$0.93
Increase option pool (in dollars per share)		$0
Granted (in dollars per share)	$6.59	$2.11
Expired/Forfeited/Exercised (in dollars per share)	$2.28	$1.95
Outstanding end of the period (in dollars per share)	$1.98	$1.32
Warrant [Member]
Numbers of Warrants [Roll Forward]
Warrants Outstanding Beginning Balance (in shares)	9,751,615	556,613
Granted (in shares)		9,195,002
Exercised (in shares)	-10
Expired (in shares)	-556,613
Retired (in shares)	-313
Warrants Outstanding Ending Balance (in shares)	9,194,679	9,751,615
Per share exercise price [Abstract]
Outstanding Beginning Balance (in dollars per share)		$10
Granted (in dollars per share)		$5
Exercised (in dollars per share)	$5
Expired (in dollars per share)	$10
Retired (in dollars per share)	$5
Weighted Average Exercise Price [Abstract]
Outstanding Beginning Balance (in dollars per share)	$5.29	$10
Granted (in dollars per share)		$5
Exercised (in dollars per share)	$5
Expired (in dollars per share)	$10
Retired (in dollars per share)	$5
Outstanding Ending Balance(in dollars per share)	$5	$5.29
Weighted average remaining contractual life	3 years 5 months 1 day	4 years 2 months 8 days
Warrant [Member] | Minimum [Member]
Per share exercise price [Abstract]
Outstanding Ending Balance (in dollars per share)		$5
Warrant [Member] | Maximum [Member]
Per share exercise price [Abstract]
Outstanding Ending Balance (in dollars per share)		$10

Shareholders_Equity_Preferred_

Shareholders' Equity, Preferred and Common Shares (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 01, 2013	Sep. 30, 2013
Preferred Shares [Abstract]
Preferred shares, shares authorized (in shares)	2,000,000	2,000,000
Preferred shares, issued and outstanding (in shares)	70,000	0
Preferred dividend (in hundredths)	3.00%
Preferred share dividend (in dollars per shares)	$1.50
Conversion price (in dollars per share)	$4
Common stock conversion ratio	12.5
Common Shares [Abstract]
Common shares, authorized (in shares)	125,000,000	125,000,000
Common shares, par value (in dollars per share)	$0	$0
Common shares, shares issued (in shares)	83,121,698	67,412,139
Common shares, shares outstanding (in shares)	78,227,756	56,714,424
Treasury stock (in shares)	4,893,942	10,697,715
Gross proceeds from issuance of common shares	$43,826,687	$22,297,209	$1,002,220
Number of warrants issued (in shares)		8,000,000
Asterias Biotherapeutics [Member]
Common Shares [Abstract]
Stock issued during period (in shares)				8,902,077
Number of warrants issued (in shares)					8,000,000
Initial exercise price of unit (in dollars per share)					$5
Cell Cure Nuerosciences ,Ltd. [Member]
Common Shares [Abstract]
Number of shares purchased (in shares)		87,456
BioTime Acquisition Corporation [Member]
Common Shares [Abstract]
Stock issued during period (in shares)		8,902,077
Warrants issued (in shares)		8,000,000
Number of shares issued in exchange for shares of The Company (in shares)		906,735
BioTime Common Stock [Member]
Common Shares [Abstract]
Shares sold (in shares)	9,431,398
Proceeds from shares sold	29,425,962
Stock price (in dollars per share)	$3.12
Number of shares purchased (in shares)	96,150
BioTime Common Stock [Member] | Asterias Biotherapeutics [Member]
Common Shares [Abstract]
Number of investors	2
Proceeds from sale of BioTime stock	12,500,000
Number of shares sold (in shares)	5,000,000
Asterias Series B Common Stock [Member] | Asterias Biotherapeutics [Member]
Common Shares [Abstract]
Number of shares purchased (in shares)	5,000,000
Broadwood Partners, LP [Member]
Common Shares [Abstract]
Number of shares purchased (in shares)	4,040,523
Broadwood Partners, LP [Member] | BioTime Common Stock [Member]
Common Shares [Abstract]
Number of shares purchased (in shares)	1,000,000
Broadwood Partners, LP [Member] | Asterias Warrants [Member]
Common Shares [Abstract]
Number of warrants issued (in shares)	1,000,000
George Karfunkel [Member] | BioTime Common Stock [Member]
Common Shares [Abstract]
Number of shares purchased (in shares)	4,000,000
George Karfunkel [Member] | Asterias Warrants [Member]
Common Shares [Abstract]
Number of warrants issued (in shares)	4,000,000
Landlord [Member]
Common Shares [Abstract]
Stock issued during period (in shares)		73,553
Market value of common shares issued		242,726
Value of common shares issued		253,758
Certain investors [Member]
Common Shares [Abstract]
Stock issued during period (in shares)		2,180,016
Gross proceeds from issuance of common shares		9,057,967
Warrants issued (in shares)		545,004
Initial exercise price of unit (in dollars per share)	$5
Number of shares in a unit (in shares)		1
Number of warrants in a unit (in shares)		0.025
Offering price of unit (in dollars per share)		$4.16
Period of option agreement		5 years
Private Investors [Member]
Common Shares [Abstract]
Stock issued during period (in shares)		1,350,000
Gross proceeds from issuance of common shares		5,000,000
Warrants issued (in shares)		649,999
Cantor Fitzgerald Controlled Equity Offering [Member]
Common Shares [Abstract]
Stock issued during period (in shares)	5,545,160	3,665,646
Gross proceeds from issuance of common shares	$17,380,668	$15,722,339

Stock_Option_Plans_Details

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)	$0.00
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
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)	$0.11
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
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
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)	$0.00
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
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

Stock_Option_Plans_Allocation_

Stock Option Plans, Allocation of Recognized Period Costs (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
All stock-based compensation expense [Abstract]
All stock-based compensation expense included in expenses	$4,455,420	$3,044,774	$1,843,962
Research and Development [Member]
All stock-based compensation expense [Abstract]
All stock-based compensation expense included in expenses	1,309,703	829,938	815,052
General and Administrative [Member]
All stock-based compensation expense [Abstract]
All stock-based compensation expense included in expenses	$3,145,717	$2,214,836	$1,028,910

Sales_of_BioTime_Common_Shares1

Sales of BioTime Common Shares by Subsidiaries (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	Investor
Related Party Transaction [Line Items]
Number of warrants issued (in shares)		8,000,000
BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	96,150
Asterias Biotherapeutics [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares sold (in shares)	5,000,000
Number of investors	2
Proceeds from sale of BioTime stock	$12,500,000
Asterias Biotherapeutics [Member] | Asterias Series B Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares sold (in shares)	200,000
Number of shares purchased (in shares)	5,000,000
Broadwood Partners, LP [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	4,040,523
Broadwood Partners, LP [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	1,000,000
Broadwood Partners, LP [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Number of warrants issued (in shares)	1,000,000
George Karfunkel [Member] | BioTime Common Stock [Member]
Related Party Transaction [Line Items]
Number of shares purchased (in shares)	4,000,000
George Karfunkel [Member] | Asterias Warrants [Member]
Related Party Transaction [Line Items]
Number of warrants issued (in shares)	4,000,000

Clinical_Trial_and_Option_Agre1

Clinical Trial and Option Agreement and CIRM Grant Award (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Revenue from Grants	$3,296,832	$1,573,329	$2,222,458
CIRM [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Grant Award	14,300,000
Clinical Trial and Option Agreement [Member] | CRUK and CRT [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Maximum percentage of sublicense revenue prior to commencement of a Phase II clinical trial (in hundredths)	40.00%
Minimum percentage of sublicense revenue after completion of a Phase III clinical trial (in hundredths)	7.50%
Notice of Grant Award [Member] | CIRM [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
Grant Award	14,300,000
Effective Date Of Grant Award Agreement	1-Oct-14
Grant term	4 years
Revenue from Grants	$916,554

Share_Exchange_and_Contributio1

Share Exchange and Contribution Agreement (Details) (Share Exchange and Contribution Agreement [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Share Exchange and Contribution Agreement [Member]
Subsidiary or Equity Method Investee [Line Items]
Percentage of ownership in subsidiary permitted to party under agreement (in hundredths)	3.75%
Stock issued during period shares under agreement by subsidiary (in shares)	66,791
Stock issued during period value under agreement by subsidiary	$117,000

Asset_Contribution_Agreement_D

Asset Contribution Agreement (Details) (USD $)	12 Months Ended			0 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 01, 2013	Jan. 04, 2013	Aug. 31, 2013	Oct. 31, 2013	Sep. 30, 2013	Sep. 30, 2014
Asset Contribution Agreement [Line Items]
Common shares, par value (in dollars per share)	$0	$0
Number of warrants issued (in shares)		8,000,000
Proceeds from issuance of common shares	$44,150,069	$25,938,558	$1,131,279
Intangible assets, useful life	10 years
Deferred tax liability arising from difference adjustment to intangible assets acquired	2,157,369
Accumulated amortization of intangible assets	269,671
Deferred income tax benefits	-7,375,611	-3,280,695	0
Amortization expense for intangible assets	1,887,698
Weighted-average assumptions [Abstract]
BioTime common shares, at fair value	0	34,985,163	0
BioTime Warrants, at fair value	0	18,276,406	0
Series A Common Stock [Member]
Asset Contribution Agreement [Line Items]
Stock price (in dollars per share)					$2.40
Warrants [Member]
Asset Contribution Agreement [Line Items]
Number of warrants to be issued by Asterias to Series A common shareholders (in shares)							8,000,000
Asterias Biotherapeutics [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)				8,902,077
Number of warrants issued (in shares)								8,000,000
Exercise price of warrant (in dollars per share)								$5
Warrant expiration term				5 years
Amount of contribution from investor				5,000,000
Weighted-average assumptions [Abstract]
Asterias Series B shares	52,164,568
Warrants to purchase Asterias Series B shares	2,012,481
Excess of contributed asset's value over consideration	4,800,063
Total consideration paid	58,977,112
BioTime common shares, at fair value	34,985,163
BioTime Warrants, at fair value	18,276,406
Cancellation of outstanding obligation to BioTime	5,000,000
Investment in affiliates, at cost	415,543
Geron asset acquisition related transaction costs paid by BioTime	300,000
Total assets transferred	58,977,112
Asterias Biotherapeutics [Member] | Asterias Series B Common Stock [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)				21,773,340
Common shares, par value (in dollars per share)								$0.00
Number of warrants issued (in shares)								3,150,000
Exercise price of warrant (in dollars per share)					$5			$5
Warrant expiration term				3 years
Stock price (in dollars per share)					$2.40
Market value of BioTime common stock (in dollars per share)								$3.93
Weighted-average assumptions [Abstract]
Expected term				5 years	3 years
Risk-free interest rate (in hundredths)				1.42%	0.63%
Dividend yield (in hundredths)				0.00%	0.00%
Expected volatility (in hundredths)				77.63%	69.62%
OrthoCyte Corporation [Member]
Asset Contribution Agreement [Line Items]
Percentage of subsidiary stock contributed (in hundredths)								10.00%
Cell Cure Neurosciences, Ltd. [Member]
Asset Contribution Agreement [Line Items]
Percentage of subsidiary stock contributed (in hundredths)								6.00%
Geron [Member]
Asset Contribution Agreement [Line Items]
Transaction costs allocated to issuance of equity				541,800
Intangible assets, useful life				10 years
Royalty rate on net sales of products (in hundredths)	4.00%
IPR&D acquisition cost capitalized		17,458,766
Deferred tax liability arising from difference adjustment to intangible assets acquired	2,157,369
Accumulated amortization of intangible assets	269,671
Deferred income tax benefits	-7,375,611
Amortization expense for intangible assets	1,887,698
Weighted-average assumptions [Abstract]
Total consideration paid									34,917,532
Asterias Series A shares, net of issuance cost of $541,800									15,121,222
Obligation to distribute BioTIme Warrants									18,276,406
Transaction and other costs				1,519,904
Patents and other intellectual property rights related to hES cells, asset contribution agreement								29,017,009
Deferred tax liability arising from difference in book versus tax basis on Geron intangible assets acquired								-11,558,243
IPR&D expensed upon acquisition								17,458,766
Total assets and in-process research and development acquired								34,917,532
Geron [Member] | Series A Common Stock [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)						6,537,779
Common shares, par value (in dollars per share)						$0.00
Romulus Films, Ltd. [Member] | Asterias Series B Common Stock [Member]
Asset Contribution Agreement [Line Items]
Stock issued during period (in shares)					2,136,000
Number of warrants issued (in shares)					350,000
Proceeds from issuance of common shares				$5,000,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Details)

12 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

USD ($)

USD ($)

USD ($)

Reporting Entities [Member]

Reporting Entities [Member]

Reporting Entities [Member]

Asterias Biotherapeutics, Inc. [Member]

Asterias Biotherapeutics, Inc. [Member]

Asterias Biotherapeutics, Inc. [Member]

ESI [Member]

ESI [Member]

LifeMap Sciences, Inc. [Member]

LifeMap Sciences, Inc. [Member]

LifeMap Sciences, Inc. [Member]

LifeMap Sciences, Inc. [Member]

LifeMap Sciences, Inc. [Member]

LifeMap Sciences, Inc. [Member]

LifeMap Sciences, Inc. [Member]

Cell Cure Neurosciences, Ltd. [Member]

Cell Cure Neurosciences, Ltd. [Member]

Office and research laboratory in Alameda [Member]

Office and research facility in La Jolla [Member]

Office space in New York City [Member]

Office space in New York City [Member]

Office and research facility in Menlo Park [Member]

Office and research facility in Fremont [Member]

Laboratory space [Member]

Laboratory space [Member]

Office space in Tel Aviv, Israel [Member]

Office space in Tel Aviv, Israel [Member]

Office space in Hong Kong [Member]

Office space in Hong Kong [Member]

Office space in Marshfield, Massachusetts [Member]

Office space in Hoboken, New Jersey [Member]

Office space in San Jose, California [Member]

Office and laboratory space, Jerusalem, Israel [Member]

Office and laboratory space, Jerusalem, Israel [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

SGD

USD ($)

ILS

USD ($)

HKD

USD ($)

USD ($)

USD ($)

USD ($)

ILS

sqft

sqft

sqm

sqm

sqm

sqm

sqm

sqm

sqm

Operating Leased Assets [Line Items]

Lease commencement date

15-Oct-13

1-Jul-14

7-Jan-13

1-Oct-14

1-Dec-13

1-Dec-13

Lease Expiration Date

28-Feb-14

28-Feb-14

31-May-15

31-May-15

30-Nov-15

30-Nov-15

30-Sep-15

28-Feb-15

30-Nov-15

30-Nov-16

30-Nov-16

Lease term

1 year 0 months 14 days

1 year

3 years

96 months

Number of years lease can be extended (in years)

5 years

Leased area

120

44,000

125

125

320

320

120

120

750

200

269

290

290

Leased area during first 15 months (in square feet)

22,000

Base rent

$31,675

$4,527

$5,050

$3,512

$31,786

$50,985

$8,300

11,000

$6,600

25,889

$970

7,500

$1,169.85

$1,150

$1,769

$5,600

21,930

Base rent increase rate (in hundredths)

3.00%

3.00%

Liable for improvement cost

84,000

328,000

Rent expenses

2,192,511

1,599,725

1,178,840

247,000

Real estate taxes during first 15 months (in hundredths)

50.00%

Levied taxes on excess assessed valuation (in hundredths)

100.00%

Tenant improvement allowance

4,400,000

4,400,000

Tenant improvement allowance expire period

18 months

Number of years, improvement cost spread

2 years 6 months

2 years 6 months

Initial base rent

5,600

21,800

Planned investment in tenant improvements

5,500,000

Security Deposit

300,000

Number of five year options to extend lease term

P2Y

Notice required to exercise five year option

1 year

Base rent effective January 1, 2016

105,142

Percentage of base rent applied to management fees (in hundredths)

3.00%

Percentage of base rent applied to escalations

3.00%

Construction costs incurred for tenant improvements

406,000

Portion of construction costs reimbursable by landlord

377,981

0

378,000

Rent expense

2,192,511

1,599,725

1,178,840

247,000

Deferred rent balance

97,280

35,997

94,000

Minimum annual lease payments under the various operating leases [Abstract]

2015

1,674,583

2016

1,437,345

2017

1,323,095

2018

1,349,664

2019

1,386,792

Thereafter

4,033,933

Total

11,205,412

Minimum annual lease payments under the Fremont operating lease [Abstract]

2015

611,820

2016

1,271,226

2017

1,309,295

2018

1,347,364

2019

1,386,792

Thereafter

4,033,933

Total

$9,960,430

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets/(liabilities) [Abstract]
Net operating loss carryforwards	$58,693,000	$46,711,000
Research & development and other credits	5,230,000	2,329,000
Patents and licenses	-8,153,000	-11,934,000
Stock options	1,561,000	0
Other, net	-246,000	737,000
Total	57,085,000	37,843,000
Valuation allowance	-66,579,000	-46,121,000
Net deferred tax (liabilities)	-9,494,000	-8,278,000
Income tax rate reconciliation [Abstract]
Computed tax benefit at federal statutory rate (in hundredths)	34.00%	34.00%	34.00%
Research & development and other credits (in hundredths)	3.00%	0.00%	0.00%
Permanent differences (in hundredths)	-1.00%	-15.00%	-3.00%
Losses for which no benefit has been recognized (in hundredths)	-24.00%	-18.00%	-28.00%
State tax benefit, net of effect on federal income taxes (in hundredths)	3.00%	4.00%	0.00%
Foreign rate differential (in hundredths)	-1.00%	1.00%	-3.00%
Total (in hundredths)	14.00%	6.00%	0.00%
Net operating loss carryforwards for federal tax purposes	122,450,000
Net operating loss carryforwards for state tax purposes	51,206,000
Tax Credit Carryforward [Line Items]
Foreign net operating loss carryforwards	54,207,000
Deferred income tax benefit	-7,375,611	-3,280,695	0
Deferred federal income tax benefit	-5,155,000	-2,800,000
Deferred state income tax benefit	-2,221,000	-480,000
Percentage of change in ownership (in hundredths)	50.00%
Period in which change of ownership for a specified percentage should occur	3 years
Federal [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	2,250,000
State [Member]
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	$2,250,000

Segment_Information_Details

Segment Information (Details)	12 Months Ended
	Dec. 31, 2014
	Segment
Segment Information [Abstract]
Number of operating segments	1

Enterprisewide_Disclosures_Det

Enterprise-wide Disclosures (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2011
	MajorGrants
	MajorCustomers
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$5,243,204	$4,434,336	$3,915,327
Revenue, Major Customer [Line Items]
Number of major customers	2
Number of major grants	3
Award granted from research project	2,640,707	1,351,735
Grants revenue	3,296,832	1,573,329	2,222,458
Hospira [Member]
Revenue, Major Customer [Line Items]
Percentage of total revenues (in hundredths)	3.00%	6.50%	11.00%
C J [Member]
Revenue, Major Customer [Line Items]
Percentage of total revenues (in hundredths)	1.00%	1.70%	2.90%
Summit [Member]
Revenue, Major Customer [Line Items]
Percentage of total revenues (in hundredths)	0.00%	20.30%	3.70%
CIRM [Member]
Revenue, Major Customer [Line Items]
Grant Award	14,300,000
Percentage of total revenues (in hundredths)	19.70%	0.00%	26.70%
OCS [Member]
Revenue, Major Customer [Line Items]
Percentage of total revenues (in hundredths)	31.30%	27.90%	26.00%
Subscription and Advertising (various customers) [Member]
Revenue, Major Customer [Line Items]
Percentage of total revenues (in hundredths)	32.50%	38.60%	28.50%
N I H [Member]
Revenue, Major Customer [Line Items]
Number of major grants	3
Percentage of total revenues (in hundredths)	12.50%	5.00%	1.20%
N I H [Member] | 2011 NIH Grant [Member]
Revenue, Major Customer [Line Items]
Award granted from research project				335,900
Payment received from research project	116,794	111,691
Grants revenue	110,237	150,239
N I H [Member] | 2013 NIH Contract [Member]
Revenue, Major Customer [Line Items]
Award granted from research project		285,423
Payment received from research project	214,068	71,355
Grants revenue	110,237	150,239
N I H [Member] | 2014 NIH Grant #1 [Member]
Revenue, Major Customer [Line Items]
Award granted from research project	270,262
Payment received from research project	71,544
Grants revenue	127,584
N I H [Member] | 2014 NIH Grant #2 [Member]
Revenue, Major Customer [Line Items]
Award granted from research project	292,262
Payment received from research project	64,899
Grants revenue	116,854
N I H [Member] | 2014 NIH Grant #3 [Member]
Revenue, Major Customer [Line Items]
Award granted from research project	224,911
Payment received from research project	63,563
Grants revenue	87,382
Cell Cure Neurosciences, Ltd. [Member]
Revenue, Major Customer [Line Items]
Grants revenue	16,606,251	1,333,901
LifeMap Sciences, Ltd. [Member]
Revenue, Major Customer [Line Items]
Payment received from research project	1,009,036	1,082,077
Grants revenue		13,838
Advertising revenue	526,003	609,314
Revenues of royalty and commission fees	647,071	707,695
ESI [Member]
Revenue, Major Customer [Line Items]
Grants revenue		3,996
Asterias [Member]
Revenue, Major Customer [Line Items]
Grants revenue	1,034,456
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	3,585,729	2,106,161	2,529,669
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$1,657,475	$2,328,175	$1,385,658

Selected_Quarterly_Financial_I2

Selected Quarterly Financial Information (UNAUDITED) (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Financial Information [Abstract]
Revenues, net	$1,664,563		$960,202		$855,435		$934,721		$1,670,063		$507,384		$1,035,514		$431,724		$5,243,204	$4,434,336	$3,915,327
Acquired in-process research and development									17,458,766	[1]	0	[1]	0	[1]	0	[1]	0	17,458,766	0
Operating expenses	16,069,154		13,097,791		13,917,109		12,072,564		13,504,740		10,709,337		9,151,965		8,811,633		55,088,726	59,626,863	28,481,733
Loss from operations	-14,404,591		-12,137,589		-13,061,674		-11,137,843		-29,293,443		-10,201,953		-8,116,451		-8,379,909		-50,682,574	-55,985,186	-25,000,677
Net loss attributable to BioTime, Inc.	($10,567,537)	[2]	($8,267,925)	[2]	($9,520,190)	[2]	($8,099,014)	[2]	($19,612,314)	[2]	($9,003,168)	[2]	($7,549,765)	[2]	($7,719,263)	[2]	($36,411,660)	($43,882,835)	($21,425,703)
Basic and diluted net loss per share (in dollars per share)	($0.14)		($0.12)		($0.16)		($0.14)		($0.35)		($0.16)		($0.14)		($0.15)		($0.55)	($0.81)	($0.44)
[1]	Includes IPR&D expenses related to intangible assets acquired by Asterias from Geron under the Asset Contribution Agreement. IPR&D represents the value of incomplete research and development projects which Asterias intends to continue. See Notes 2 and 14.
[2]	Net of $7,375,611 and $3,280,695 income tax benefits in fourth quarter for 2014 and 2013 respectively.

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jan. 31, 2015	Feb. 28, 2015
Sale of Common Shares [Abstract]
Proceeds from issuance of common shares	$44,150,069	$25,938,558	$1,131,279
Subsequent Event [Member] | Asterias Biotherapeutics, Inc. [Member] | CIRM [Member]
Subsequent Event [Line Items]
Payment received from CIRM				2,269,515
Subsequent Event [Member] | Series A Common Stock [Member] | Asterias Biotherapeutics, Inc. [Member]
Sale of Common Shares [Abstract]
Proceeds from issuance of common shares					$5,500,000
Number of shares issued through public offering (in shares)					1,410,255
Stock price (in dollars per share)					$3.90
Number of shares issued through private placement (in shares)					1,025,640