Servicing rights - Assumptions (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
SBA servicing rights
Adverse changes to key assumptions on the carrying amount of the servicing rights
Prepayment rate (10% adverse change)	$ (1,164)	$ (543)
Prepayment rate (20% adverse change)	(2,261)	(1,069)
Default rate (10% adverse change)	(162)	(165)
Default rate (20% adverse change)	(323)	(328)
Discount rate (10% adverse change)	(1,244)	(1,530)
Discount rate (20% adverse change)	(2,401)	(2,922)
Cost of servicing (10% adverse change)	(2,258)	(2,047)
Cost of servicing (20% adverse change)	(4,515)	(4,095)
Multi-family servicing rights
Adverse changes to key assumptions on the carrying amount of the servicing rights
Prepayment rate (10% adverse change)	(466)	(491)
Prepayment rate (20% adverse change)	(918)	(965)
Default rate (10% adverse change)	(14)	(14)
Default rate (20% adverse change)	(27)	(29)
Discount rate (10% adverse change)	(2,238)	(2,320)
Discount rate (20% adverse change)	(4,365)	(4,524)
Cost of servicing (10% adverse change)	(2,567)	(2,587)
Cost of servicing (20% adverse change)	(5,135)	$ (5,173)
USDA
Adverse changes to key assumptions on the carrying amount of the servicing rights
Prepayment rate (10% adverse change)	(804)
Prepayment rate (20% adverse change)	(1,543)
Discount rate (10% adverse change)	(485)
Discount rate (20% adverse change)	(942)
Cost of servicing (10% adverse change)	(625)
Cost of servicing (20% adverse change)	$ (1,250)