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DIVESTITURE OF STEM CELL ASSETS (Details) (USD $)				0 Months Ended
	May 28, 2014	Jun. 30, 2014 Series A common stock	Oct. 01, 2013 Series A common stock	May 28, 2014 Asterias contributions Series A common stock	Oct. 01, 2013 Contribution Agreement Asterias contributions Geron
DIVESTITURE OF STEM CELL ASSETS
Shares issued					6,537,779
Percentage ownership in Asterias					21.40%
Number of shares of entity's common stock outstanding	156,924,100
Common stock distribution ratio				0.0417
Carrying value of common stock		$ 0	$ 0
Liability relating to contractual obligation to distribute common stock		$ 0

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- Definition

Represents the carrying value assigned to Asterias Series A common stock received in stem cell divestiture.

+ References

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- Definition

Represents the distribution ratio for the number of shares of Asterias Series A common stock that shareholders will receive for one share of Geron common stock.

+ References

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Percentage of investee's stock owned immediately after all stock transactions.

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- Definition

Represents the amount of liability related to contractual obligation to distribute Asterias Series A common stock received in stem cell divestiture.

+ References

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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-Publisher SEC

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The number of shares issued as [noncash or part noncash] consideration for a business or asset acquired. Noncash is defined as transactions during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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