Servicing rights (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Servicing rights
Unpaid Principal Amount	$ 6,898,073	$ 5,858,798
Carrying Value	102,837	87,117
Total servicing rights	102,837	87,117
Servicing rights activity at amortized cost
Beginning net carrying value at amortized cost	87,117
Ending net carrying value at amortized cost	102,837	87,117
SBA servicing rights
Servicing rights
Carrying Value	29,536	19,756
Servicing rights activity at amortized cost
Beginning net carrying value at amortized cost	19,756	22,157
Additions due to loans sold, servicing retained	6,976	7,608
Amortization	(3,450)	(3,817)
Impairment (recovery)	6,254	(6,192)
Ending net carrying value at amortized cost	29,536	19,756
Multi-family servicing rights
Servicing rights
Unpaid Principal Amount	5,689,872	4,839,028
Carrying Value	73,301	67,361
Servicing rights activity at amortized cost
Beginning net carrying value at amortized cost	67,361	62,300
Additions due to loans sold, servicing retained	16,655	14,705
Amortization	(10,715)	(9,644)
Ending net carrying value at amortized cost	73,301	67,361
SBA | SBA servicing rights
Servicing rights
Unpaid Principal Amount	1,208,201	1,019,770
Carrying Value	29,536	19,756
Servicing rights activity at amortized cost
Beginning net carrying value at amortized cost	19,756
Ending net carrying value at amortized cost	$ 29,536	$ 19,756