Fair value of financial instruments and marketable securities - Marketable Securities (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended	9 Months Ended
Jan. 31, 2020	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Changes in fair value
Unrealized Gain/(Loss)				$ 3,160	$ 1,923
Investments Purchased				46,537	49,614
Redemptions/Sale				(40,112)	(41,624)
Unrealized Gain/(Loss)				5,734	3,954
Ending Balance			$ 10,028		10,028
Unrealized Gain/(Loss)					(1,931)
Realized Loss					(622)
Redemptions/Sale					(10,000)
Beginning Balance - Total		$ 44,884	32,333	42,793	41,261
Unrealized Gain/(Loss) - Total		10,434	6,018	8,894	3,946
Realized Loss - Total			(622)		(622)
Foreign Currency Unrealized Gain/(Loss) - Total		1,605	400	5,337	(3,289)
Investments Purchased - Total		29,508	32,208	46,537	49,614
Redemptions/Sale - Total		(22,982)	(31,051)	(40,112)	(51,624)
Ending Balance - Total		63,449	39,286	63,449	39,286
ClearPoint Convertible note
Purchase of convertible note				1,051,267	476,680
Marketable securities - equity investments
Changes in fair value
Beginning Balance		34,203	16,889	29,034	22,634
Unrealized Gain/(Loss)		1,622	812	3,160	1,923
Foreign Currency Unrealized Gain/(Loss)		1,605	400	5,337	(3,289)
Investments Purchased		29,508	32,208	46,537	49,614
Redemptions/Sale		(22,982)	(21,051)	(40,112)	(41,624)
Ending Balance		43,956	29,258	43,956	29,258
ClearPoint Equity Investment
Changes in fair value
Beginning Balance		10,681	4,822	13,759	6,074
Unrealized Gain/(Loss)		8,812	5,206	5,734	3,954
Ending Balance		19,493	10,028	19,493	10,028
ClearPoint convertible debt
Changes in fair value
Redemptions/Sale			(10,000)		(10,000)
Beginning Balance			10,622		12,553
Unrealized Gain/(Loss)					(1,931)
Realized Loss			$ (622)		$ (622)
Ending Balance		$ 0		$ 0
ClearPoint Convertible note
Purchase of convertible note	$ 10,000
Conversion price - convertible note	$ 6
Term of convertible note	5 years

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Amount of unrealized gain (loss) on ClearPoint equity investment measured at fair value with change in fair value recognized in net income (FV-NI).

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The cash inflow associated with a principal/settlement payment received by the entity on Clearpoint convertible debt security during the period.

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The cash inflow associated with the aggregate amount received by the entity through sale or redemption of marketable equity investments and convertible debt securities during the period.

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Amount of realized gain (loss) 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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of cash outflow to acquire 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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The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities (held-to-maturity or available-for-sale) during the period.

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