Transfers of financial assets and servicing assets - Key economic assumptions used (Details) - Residential Mortgage	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 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	4.70%	5.90%	5.00%	7.40%
Weighted average life	10 years 2 months 12 days	8 years 10 months 24 days	9 years 9 months 18 days	8 years
Discount rate (annual rate)	10.50%	10.40%	10.40%	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	7.80%	12.50%	8.90%	21.20%
Weighted average life	8 years	6 years	7 years 4 months 24 days	9 years 6 months
Discount rate (annual rate)	9.50%	11.00%	9.80%	11.00%