Investments in marketable securities - Marketable Securities (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Cash and Cash Equivalents [Abstract]
Cash Equivalents, at Carrying Value	$ 8,901	$ 10,218
Cash Equivalents, Fair Value Disclosure	8,901	10,218
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	73,513	73,376
Gross Unrealized Gain	1	87
Gross Unrealized Loss	(60)	0
Fair Value	73,454	73,463
Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Fair Value	73,500	73,500
Money market funds
Cash and Cash Equivalents [Abstract]
Money Market Funds, at Carrying Value	6,914	10,218
US treasury bills
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	37,512	37,411
Gross Unrealized Gain	1	41
Gross Unrealized Loss	(30)	0
Fair Value	37,483	37,452
US Government Securities, at Carrying Value	1,987
Debt Securities, Unrealized Gain (Loss)	0
Financial Instruments, Owned, US Government and Agency Obligations, at Fair Value	1,987
US government bonds \| Short Term Marketable Securities
Debt Securities, Available-for-Sale [Abstract]
Amortized Cost	36,001	35,965
Gross Unrealized Gain	0	46
Gross Unrealized Loss	(30)	0
Fair Value	$ 35,971	$ 36,011

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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The fair value as of the balance sheet date of firm holdings in debt obligations issued by the US government including short-term Treasury bills, medium-term Treasury notes, and long-term Treasury bonds, as well as debt issued by agencies. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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Debt (bills, notes or bonds) that are issued by the government of the United States which are 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. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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