Transfers of financial assets and servicing assets - Key economic assumptions used (Details) - Residential Mortgage	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
BPPR
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement
Prepayment speed	5.50%	5.80%	5.20%	6.90%
Weighted average life	9 years 6 months	8 years 9 months 18 days	9 years 8 months 12 days	8 years 3 months 18 days
Discount rate (annual rate)	10.70%	10.50%	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
Prepayment speed	7.20%	13.70%	8.40%	20.50%
Weighted average life	8 years 2 months 12 days	5 years 10 months 24 days	7 years 8 months 12 days	15 years 4 months 24 days
Discount rate (annual rate)	10.00%	10.00%	9.80%	10.90%