Fair value measurement - Schedule of the Company's Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Assets:
Available-for-sale securities:	$ 68,917	$ 13,826
Fair Value, Recurring
Assets:
Assets	93,997	102,945
Fair Value, Recurring | U.S. government securities
Assets:
Available-for-sale securities:	16,901	1,494
Fair Value, Recurring | Corporate debt securities
Assets:
Available-for-sale securities:	41,358	9,000
Fair Value, Recurring | Other debt securities
Assets:
Available-for-sale securities:	10,658	3,332
Fair Value, Recurring | Convertible promissory note
Assets:
Available-for-sale securities:	2,041
Fair Value, Recurring | Level 1
Assets:
Assets	45,944	91,011
Fair Value, Recurring | Level 1 | U.S. government securities
Assets:
Available-for-sale securities:	16,901	1,494
Fair Value, Recurring | Level 1 | Corporate debt securities
Assets:
Available-for-sale securities:	6,004	398
Fair Value, Recurring | Level 1 | Other debt securities
Assets:
Available-for-sale securities:	0	0
Fair Value, Recurring | Level 1 | Convertible promissory note
Assets:
Available-for-sale securities:	0
Fair Value, Recurring | Level 2
Assets:
Assets	46,012	11,934
Fair Value, Recurring | Level 2 | U.S. government securities
Assets:
Available-for-sale securities:	0	0
Fair Value, Recurring | Level 2 | Corporate debt securities
Assets:
Available-for-sale securities:	35,354	8,602
Fair Value, Recurring | Level 2 | Other debt securities
Assets:
Available-for-sale securities:	10,658	3,332
Fair Value, Recurring | Level 2 | Convertible promissory note
Assets:
Available-for-sale securities:	0
Fair Value, Recurring | Level 3
Assets:
Assets	2,041	0
Fair Value, Recurring | Level 3 | U.S. government securities
Assets:
Available-for-sale securities:	0	0
Fair Value, Recurring | Level 3 | Corporate debt securities
Assets:
Available-for-sale securities:	0	0
Fair Value, Recurring | Level 3 | Other debt securities
Assets:
Available-for-sale securities:	0	0
Fair Value, Recurring | Level 3 | Convertible promissory note
Assets:
Available-for-sale securities:	2,041
Fair Value, Recurring | Money market accounts
Assets:
Cash equivalents:	23,039	89,119
Fair Value, Recurring | Money market accounts | Level 1
Assets:
Cash equivalents:	23,039	89,119
Fair Value, Recurring | Money market accounts | Level 2
Assets:
Cash equivalents:	0	0
Fair Value, Recurring | Money market accounts | Level 3
Assets:
Cash equivalents:	$ 0	$ 0