Fair value measurements - Assets and liabilities measured on a recurring basis - (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Assets, Fair Value Disclosure
Money market funds included in cash and cash equivalents	$ 74,755	$ 71,367
Fair value, measurements, recurring
Assets, Fair Value Disclosure
Total money market funds and marketable securities	289,094	320,679
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Total money market funds and marketable securities	215,709	212,959
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Total money market funds and marketable securities	73,385	107,720
U.S. Treasury notes | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	130,578	125,783
U.S. Treasury notes | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	130,578	125,783
U.S. Government agency securities | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	16,404	27,518
U.S. Government agency securities | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	16,404	27,518
Certificates of deposit | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	3,320	4,286
Certificates of deposit | Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	3,320	4,286
Corporate bonds | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	61,394	94,976
Corporate bonds | Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	61,394	94,976
Commercial paper | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	8,671	8,458
Commercial paper | Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Marketable securities	8,671	8,458
Money market funds
Assets, Fair Value Disclosure
Money market funds included in cash and cash equivalents	68,731	59,658
Money market funds | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Money market funds included in cash and cash equivalents	68,727	59,658
Money market funds | Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value, measurements, recurring
Assets, Fair Value Disclosure
Money market funds included in cash and cash equivalents	$ 68,727	$ 59,658