Revenue - Deferred revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenue
Balance, beginning of the period	$ 210,885	$ 154,777	$ 68,436
Deferral of revenue	65,708	185,688	146,674
Recognition of deferred revenue	(138,419)	(129,580)	(60,333)
Balance, end of the period	138,174	$ 210,885	$ 154,777
Reclassification from deferred revenue to refund liability	$ 12,700