Allowance for credit losses - Troubled debt restructuring according to their accruing status - Subnote (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable
Financing Receivable Modifications Recorded Investment	$ 1,649,158	$ 1,656,822
Accruing
Financing Receivable
Financing Receivable Modifications Recorded Investment	1,486,072	1,468,966
Mortgages
Financing Receivable
Financing Receivable Modifications Recorded Investment	1,253,778	1,255,713
Mortgages | Accruing
Financing Receivable
Financing Receivable Modifications Recorded Investment	1,160,469	1,143,204
Mortgages | Guaranteed by us sponsored entities | Accruing
Financing Receivable
Financing Receivable Modifications Recorded Investment	$ 724,000	$ 716,000