Business acquisition estimated fair value assets of free shares.

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Business acquisition estimated fair value liabilities of free shares.

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Business acquisition, number of free shares held by the holders.

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Business acquisition, number of shares acquired.

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Business acquisition, percentage of equity interests agreed to acquire.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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The cash outflow associated with the purchase of noncontrolling interest during the period.

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Acquisition of Sangamo Therapeutics France S.A.S. - Additional Information (Detail) - USD ($)			3 Months Ended		9 Months Ended		12 Months Ended
	Nov. 23, 2018	Oct. 01, 2018	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jul. 20, 2018
Business Acquisition [Line Items]
Purchase of additional Sangamo France shares					$ 262,000	$ 0
Goodwill impairments					$ 0		$ 0
TxCell S.A.
Business Acquisition [Line Items]
Number of ordinary shares acquired (in shares)		13,519,036	111,000	11,528,635
Purchase of additional Sangamo France shares			$ 300,000
Purchase price per share (usd per share)		$ 2.99
TxCell S.A. \| Share Purchase Agreement and Tender Offer Agreement
Business Acquisition [Line Items]
Percentage of equity interests agreed to acquire								100.00%
Number of ordinary shares acquired (in shares)	11,528,635		111,000	25,047,671
Number of free shares held by the holders (in shares)		477,000	477,000		477,000
Purchase of additional Sangamo France shares			$ 300,000
Estimated fair value liability of free shares		$ 200,000
Estimated fair value asset of free shares			$ 200,000		$ 200,000
TxCell S.A. \| Share Purchase Agreement and Tender Offer Agreement \| Option Pricing Method
Business Acquisition [Line Items]
Estimated fair value liability of free shares		$ 200,000		$ 200,000			$ 200,000
TxCell S.A. \| Share Purchase Agreement and Tender Offer Agreement \| Former Executive of TxCell
Business Acquisition [Line Items]
Number of ordinary shares acquired (in shares)			52,700
TxCell S.A. \| SPA
Business Acquisition [Line Items]
Number of ordinary shares acquired (in shares)		13,519,036
TxCell S.A.
Business Acquisition [Line Items]
Noncontrolling interest ownership percentage			98.70%	98.20%	98.70%		98.20%
TxCell S.A. \| Share Purchase Agreement and Tender Offer Agreement
Business Acquisition [Line Items]
Noncontrolling interest ownership percentage			98.70%	98.20%	98.70%		98.20%