Subsequent Events	12 Months Ended
Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent Events On January 13, 2022, to obtain funding for working capital purposes, the Company issued an unsecured, non-convertible promissory note in the principal amount of $2.9 million (the "2022 Promissory Note”) to Dr. Semechkin. In exchange, Dr. Semechkin surrendered the New Note and provided an additional $250 thousand of funds to the Company. The 2022 Promissory Note, including outstanding amounts of principal and accrued interest, is due and payable March 15, 2022, but may be pre-paid by the Company without penalty at any time. On March 1, 2022, the Company and Dr. Andrey Semechkin, the Company’s Chief Executive Officer, agreed to extend the maturity date of the 2022 Promissory Note for an additional six-month period to September 15, 2022. No other terms of the 2022 Promissory Note were modified.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

Name:	us-gaap_SubsequentEventsTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration