Non-consolidated VIEs - Corporation's VI in non-consolidated VIEs and max exposure to loss (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023	Jun. 30, 2023
Variable Interest Entity [Line Items]
Assets	$ 72,845,072	$ 70,758,155	$ 70,838,266
Variable Interest Entity Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	95,682	99,290
Maximum exposure to loss	95,682	99,290
Variable Interest Entity Not Primary Beneficiary | Servicing assets
Variable Interest Entity [Line Items]
Assets	88,782	92,999
Variable Interest Entity Not Primary Beneficiary | Mortgage servicing rights
Variable Interest Entity [Line Items]
Assets	88,782	92,999
Variable Interest Entity Not Primary Beneficiary | Other assets
Variable Interest Entity [Line Items]
Assets	6,900	6,291
Variable Interest Entity Not Primary Beneficiary | Servicing advances
Variable Interest Entity [Line Items]
Assets	$ 6,900	$ 6,291