Fair value measurements - Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets:
Cash and cash equivalents	$ 144,067	$ 221,755
Beneficiary interest in factored invoices	1,440	560
Total	145,507	222,315
U.S. government agency securities and treasuries
Assets:
Marketable securities:	0	0
Quoted prices in active markets (Level 1)
Assets:
Cash and cash equivalents	144,067	221,755
Beneficiary interest in factored invoices	0	0
Total	144,067	221,755
Quoted prices in active markets (Level 1) | U.S. government agency securities and treasuries
Assets:
Marketable securities:	0	0
Significant other observable inputs (Level 2)
Assets:
Cash and cash equivalents	0	0
Beneficiary interest in factored invoices	0	0
Total	0	0
Significant other observable inputs (Level 2) | U.S. government agency securities and treasuries
Assets:
Marketable securities:	0	0
Significant unobservable inputs (Level 3)
Assets:
Cash and cash equivalents	0	0
Beneficiary interest in factored invoices	1,440	560
Total	1,440	560
Significant unobservable inputs (Level 3) | U.S. government agency securities and treasuries
Assets:
Marketable securities:	$ 0	$ 0