Transfers of financial assets and servicing assets - Key economic assumptions used (Details) - Residential Mortgage	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
BPPR
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Weighted average prepayment speed (annual rate)	5.40%	6.80%
Weighted average life (in years)	9 years 6 months	8 years 3 months 18 days
Discount rate (annual rate)	10.50%	10.50%
PB
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Weighted average prepayment speed (annual rate)	8.10%	19.00%
Weighted average life (in years)	7 years 9 months 18 days	20 years 10 months 24 days
Discount rate (annual rate)	9.90%	10.70%