Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss attributable to BioTime, Inc.	$ (45,990)	$ (19,976)
Net loss attributable to noncontrolling interest	(794)	(3,313)
Adjustments to reconcile net loss attributable to BioTime, Inc. to net cash used in operating activities:
Gain on sale of equity method investment in Ascendance	(3,215)
Acquired in-process research and development	800
Unrealized gain on marketable equity securities	(1,158)
Income tax benefit	(346)
Depreciation expense, including amortization of leasehold improvements	1,081	947
Amortization of intangible assets	2,192	2,349
Stock-based compensation	5,402	3,932
Liability classified warrants	(384)	797
Amortization of discount on related party convertible debt		640
Foreign currency remeasurement and other (gain) loss	1,788	(1,761)
Gain on sale of assets		(1,754)
Loss on extinguishment of related party debt		2,799
Changes in operating assets and liabilities:
Accounts and grants receivable, net	46	(172)
Due from affiliates	559	1,157
Prepaid expenses and other current assets	(437)	145
Other long-term assets and liabilities	(487)	(22)
Accounts payable and accrued liabilities	1,100	1,299
Deferred revenues and grant income	(287)	243
Deferred grant expense		(227)
Deferred rent liabilities	144	55
Net cash used in operating activities	(30,882)	(30,517)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from the sale of AgeX common stock to Juvenescence	21,600
Proceeds from the sale of equity method investment in Ascendance	3,215
Purchase of in-process research and development by AgeX	(1,872)
Purchase of property and equipment	(556)	(1,326)
Payments on construction in progress	(859)
Purchase of foreign available-for-sale securities		(189)
Proceeds from sale of assets		200
Security deposit paid and other	(8)	(12)
Net cash provided by (used in) investing activities	11,816	(10,225)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common shares		48,875
Fees paid on sale of common shares		(3,798)
Proceeds from exercise of stock options		25
Common shares received and retired for employee taxes paid	(203)	(45)
Proceeds from exercise of subsidiary stock options and warrants		4
Proceeds from sale of subsidiary common shares and warrants	6,000	9,968
Proceeds from sale of common shares at-the-market, net of fees		835
Purchase and retirement of common shares from a related party		(843)
Repayment of lease liability and capital lease obligation	(248)	(204)
Reimbursement from landlord on construction in progress	364	198
Proceeds from issuance of related party convertible debt		425
Repayment of promissory notes	(101)	(49)
Payment to repurchase subsidiary shares	(38)
Net cash provided by financing activities	5,774	55,391
Effect of exchange rate changes on cash, cash equivalents and restricted cash	6	101
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(13,286)	14,750
At beginning of year	37,685	22,935
At end of year	24,399	37,685
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid during year for interest	155	156
SUPPLEMENTAL SCHEDULE OF NONCASH FINANCING AND INVESTING ACTIVITIES:
Sale of AgeX common stock in exchange for a promissory note from Juvenescence	21,600
Distribution of AgeX common stock to BioTime shareholders, on a pro rata basis, as a dividend-in-kind, at fair value	34,409
BioTime common stock issued to purchase Cell Cure ordinary shares and Convertible Notes from noncontrolling interests in Cell Cure		15,217
Extinguishment of related party convertible debt, including accrued interest, with BioTime common stock		2,680
Capital expenditure funded by capital lease liability		151
Landlord receivable and lease liability	840
Construction in progress in accounts payable and accrued expenses	455
AgeX Therapeutics, Inc. [Member]
Adjustments to reconcile net loss attributable to BioTime, Inc. to net cash used in operating activities:
Gain on sale of shares and deconsolidation	(78,511)
Unrealized loss on equity method investment at fair value	4,181
CASH FLOWS FROM INVESTING ACTIVITIES:
Deconsolidation of cash and cash equivalents	(9,704)
OncoCyte Corporation [Member]
Adjustments to reconcile net loss attributable to BioTime, Inc. to net cash used in operating activities:
Gain on sale of shares and deconsolidation		(71,697)
Unrealized loss on equity method investment at fair value	47,985	2,935
CASH FLOWS FROM INVESTING ACTIVITIES:
Deconsolidation of cash and cash equivalents		(8,898)
Asterias Biotherapeutics [Member]
Adjustments to reconcile net loss attributable to BioTime, Inc. to net cash used in operating activities:
Unrealized loss on equity method investment at fair value	$ 35,449	$ 51,107