Transfers of financial assets and servicing assets - Key economic assumptions used (Details) - Residential Mortgage	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
BPPR
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Prepayment speed	7.40%	4.70%	7.00%	5.00%
Weighted average life	9 years 8 months 12 days	10 years 2 months 12 days	9 years 1 month 6 days	9 years 9 months 18 days
Discount rate (annual rate)	9.50%	10.50%	9.50%	10.40%
PB
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Prepayment speed	7.10%	7.80%	7.20%	8.90%
Weighted average life	8 years 1 month 6 days	8 years	8 years	7 years 4 months 24 days
Discount rate (annual rate)	10.50%	9.50%	10.50%	9.80%