Non-controlling interests - Summary of Changes in the Balances Non-controlling Interests (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Beginning Balance	$ (4,592)	$ (16,486)	$ 4,981	$ 9,373	$ (16,486)	$ 9,373
Distributions	(7,640)		(6,832)		(10,117)	(7,748)
Net income (loss)	6,070		(2,561)		10,264	(4,099)
Ending Balance	4,693	(4,592)	4,443	4,981	4,693	4,443
BT HoldCo
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Beginning Balance	9,937	4,472	18,879	22,480	4,472	22,480
Distributions	(7,640)	(2,477)	(6,832)	(916)
Distribution related to Up-C Restructuring	(8,595)
Foreign currency translation	(59)	(89)	4	9
Redemption of non-controlling interest			(585)
Net income (loss)	6,357	8,031	6,871	(2,694)
Ending Balance		9,937	18,337	18,879		18,337
Total
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Beginning Balance	12,570	7,146	21,598	25,187	7,146	25,187
Distributions	(7,640)	(2,477)	(6,832)	(916)
Share-based compensation expense	8	8	8	8
Distribution related to Up-C Restructuring	(8,595)
Foreign currency translation	(59)	(89)	4	9
Redemption of non-controlling interest			(585)
Net income (loss)	6,253	7,982	6,911	(2,690)
Ending Balance	2,537	12,570	21,104	21,598	2,537	21,104
Bit Access [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Beginning Balance	2,633	2,674	2,719	2,707	2,674	2,707
Share-based compensation expense	8	8	8	8
Net income (loss)	(104)	(49)	40	4
Ending Balance	$ 2,537	$ 2,633	$ 2,767	$ 2,719	$ 2,537	$ 2,767