Summary of significant accounting policies - Prior Period Adjustments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023
Error Corrections and Prior Period Adjustments Restatement
Allowance for credit losses	$ 21,895
Overstatement of allowance for credit losses
Error Corrections and Prior Period Adjustments Restatement
Allowance for credit losses			$ 1,500
Overstatement of allowance for credit losses | Adoption of ASU 2016-13
Error Corrections and Prior Period Adjustments Restatement
Allowance for credit losses	$ 1,100	$ 1,100	$ 400