Fair value measurements (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2024	Dec. 31, 2023
Fabled Copper Corp. \| Sale, not discontinued operations \| Binding Letter of Intent Agreement
Fair value Assumptions
Consideration received in shares \| shares	200,000
Level 1 \| Fabled Copper Corp. \| Binding Letter of Intent Agreement
Fair value Assumptions
Investment shares held (in shares)		20,000
Fair Value, Measurements, Recurring
Fair value measurements
Cash and cash equivalents	$ 1,777	$ 3,766
Short-term investments		11
Assets	1,777	3,777
Fair Value, Measurements, Recurring \| Level 1
Fair value measurements
Cash and cash equivalents	1,777	3,766
Short-term investments		11
Assets	$ 1,777	$ 3,777

The number of shares received for consideration.

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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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Number of shares of investment owned.

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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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