Spinoff Transaction, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net

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- Definition

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

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- Definition

Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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- Definition

The net amount of nonoperating interest income (expense).

+ References

No definition available.

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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- Definition

The cash inflow from parent as a source of financing that is recorded as additional paid in capital.

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- Definition

Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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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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Summary of significant accounting policies and basis of presentation - Narrative (Detail)	12 Months Ended
	Dec. 31, 2022 USD ($) segment shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($)	Nov. 04, 2021 USD ($)	Nov. 03, 2021 shares
Restricted Cash and Cash Equivalents Items [Line Items]
Transfers from bluebird bio	$ 0	$ 354,889,000	$ 90,054,000
Net assets				$ 384,500,000
Number of operating segments \| segment	1
Accumulated goodwill impairment loss	$ 0
Interest income	$ 2,932,000	$ 88,000	0
Common stock, shares outstanding (in shares) \| shares	37,928,000	23,585,000			0
Restricted cash included in restricted cash and other non-current assets	$ 33,026,000	$ 32,852,000	$ 0
Letter of credit
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in restricted cash and other non-current assets	$ 30,000,000