Guarantees - Credit recourse - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Guarantee on loans sold or serviced with credit recourse
Guarantor Obligations [Line Items]
Valuation allowances and reserves balance	$ 6,897,000	$ 11,800,000	$ 22,484,000
Serviced mortgage loans
Guarantor Obligations [Line Items]
Loans serviced	11,100,000,000	12,100,000,000
Loans with recourse
Guarantor Obligations [Line Items]
Loans serviced	600,000,000	700,000,000
Loans with recourse | Serviced mortgage loans
Guarantor Obligations [Line Items]
Repurchased loans	7,000,000	19,000,000
Securitization | Guarantee on loans sold or serviced with representation and warranties
Guarantor Obligations [Line Items]
Repurchased loans	$ 1,000,000	$ 0