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Fair Value Measurements - Fair Value Hierarchy (Details) $ in Thousands	1 Months Ended
	Mar. 31, 2024 item instrument	Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Assets:
Number of Freestanding Financial Instruments | instrument	2
Series C redeemable convertible preferred stock
Assets:
Number of Freestanding Financial Instruments | item	2
Recurring
Assets:
Total assets		$ 373,641	$ 287,584
Recurring | Money market funds
Assets:
Cash equivalents		61,174	168,847
Recurring | U.S. Treasury obligations
Assets:
Marketable securities		237,907	118,737
Recurring | Corporate debt obligations
Assets:
Marketable securities		38,049
Recurring | Commercial paper
Assets:
Marketable securities		22,535
Recurring | Supranational debt obligations
Assets:
Marketable securities		9,963
Recurring | Government development bank obligations
Assets:
Marketable securities		4,013
Level 1 | Recurring
Assets:
Total assets		234,505	215,984
Level 1 | Recurring | Money market funds
Assets:
Cash equivalents		61,174	168,847
Level 1 | Recurring | U.S. Treasury obligations
Assets:
Marketable securities		173,331	47,137
Level 2 | Recurring
Assets:
Total assets		139,136	71,600
Level 2 | Recurring | U.S. Treasury obligations
Assets:
Marketable securities		64,576	$ 71,600
Level 2 | Recurring | Corporate debt obligations
Assets:
Marketable securities		38,049
Level 2 | Recurring | Commercial paper
Assets:
Marketable securities		22,535
Level 2 | Recurring | Supranational debt obligations
Assets:
Marketable securities		9,963
Level 2 | Recurring | Government development bank obligations
Assets:
Marketable securities		$ 4,013

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Fair value portion of asset recognized for present right to economic benefit.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes 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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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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