Basis of Presentation - Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Depreciation and amortization	$ 24	$ 24	$ 95	$ 95
Cara Therapeutics, Inc.
Depreciation and amortization	$ 0	$ 42	$ 192	$ 259	$ 248

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration