v3.25.2

Stockholders' Equity - Schedule of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2025 USD ($) $ / shares shares	Dec. 31, 2024 USD ($) $ / shares shares
Number of Options
Outstanding, beginning of period (in shares) \| shares	5,766,927
Granted (in shares) \| shares	2,632,163
Exercised (in shares) \| shares	(243,684)
Expired (in shares) \| shares	(786)
Cancelled/Forfeited (in shares) \| shares	(72,377)
Outstanding, end of period (in shares) \| shares	8,082,243	5,766,927
Exercisable (in shares) \| shares	4,242,694
Unvested (in shares) \| shares	3,839,549
Weighted Average Exercise Price Per Share
Outstanding, beginning of period (in dollars per share) \| $ / shares	$ 7.23
Granted (in dollars per share) \| $ / shares	15.76
Exercised (in dollars per share) \| $ / shares	6.14
Expired (in dollars per share) \| $ / shares	16.25
Cancelled/Forfeited (in dollars per share) \| $ / shares	9.88
Outstanding, end of period (in dollars per share) \| $ / shares	10.01	$ 7.23
Weighted Average Exercise Price, Exercisable (in dollars per share) \| $ / shares	8.57
Weighted Average Exercise Price, Unvested (in dollars per share) \| $ / shares	$ 11.61
Weighted Average Remaining Contractual Term (in years) and Aggregate Intrinsic Value
Weighted Average Remaining Contractual Term (in years), Outstanding	7 years 10 months 24 days	7 years 6 months
Weighted Average Remaining Contractual Term (in years), Granted	9 years 7 months 6 days
Weighted Average Remaining Contractual Term (in years), Exercisable	6 years 8 months 12 days
Weighted Average Remaining Contractual Term (in years), Unvested	9 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding \| $	$ 35,672	$ 28,796
Aggregate Intrinsic Value, Exercisable \| $	22,968
Aggregate Intrinsic Value, Unvested \| $	$ 12,704

Share-Based Compensation Arrangement by Share-Based Payment Award, Option, Unvested, Weighted Average Exercise Price

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of non-vested options outstanding.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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DELCATH SYSTEMS, INC. 10-Q