Loans - Amortized cost basis and interest income recognized on non-accrual loans (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	$ 143,027	$ 125,958
Non-accrual with allowance	211,100	231,653
Construction
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance		0
Non-accrual with allowance		6,378
Mortgages
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	83,033	84,797
Non-accrual with allowance	111,511	101,500
Commercial | Commercial multi-family
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	8,700	0
Non-accrual with allowance	106	1,991
Commercial | CRE non-owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	4,979	3,695
Non-accrual with allowance	5,350	6,167
Commercial | CRE owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	21,418	24,309
Non-accrual with allowance	8,583	11,395
Commercial | Commercial and Industrial
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	18,914	6,991
Non-accrual with allowance	16,680	29,607
Leasing
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	453	481
Non-accrual with allowance	6,814	8,151
Consumer | Home equity lines of credit
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	3,986	3,733
Consumer | Personal loans
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	3,458	3,589
Non-accrual with allowance	17,702	18,247
Consumer | Auto Loan
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	1,809	1,833
Non-accrual with allowance	39,998	43,782
Consumer | Other
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	263	263
Non-accrual with allowance	370	702
Puerto Rico
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	128,916	121,961
Non-accrual with allowance	169,678	206,757
Puerto Rico | Construction
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance		0
Non-accrual with allowance		6,378
Puerto Rico | Mortgages
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	82,843	84,677
Non-accrual with allowance	83,630	90,429
Puerto Rico | Commercial | Commercial multi-family
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	106	1,991
Puerto Rico | Commercial | CRE non-owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	3,635	3,695
Non-accrual with allowance	4,287	5,050
Puerto Rico | Commercial | CRE owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	17,541	20,432
Non-accrual with allowance	8,583	8,998
Puerto Rico | Commercial | Commercial and Industrial
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	18,914	6,991
Non-accrual with allowance	10,257	25,835
Puerto Rico | Leasing
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	453	481
Non-accrual with allowance	6,814	8,151
Puerto Rico | Consumer | Home equity lines of credit
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	0	0
Puerto Rico | Consumer | Personal loans
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	3,458	3,589
Non-accrual with allowance	15,634	15,442
Puerto Rico | Consumer | Auto Loan
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	1,809	1,833
Non-accrual with allowance	39,998	43,782
Puerto Rico | Consumer | Other
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	263	263
Non-accrual with allowance	369	701
Popular U.S.
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	14,111	3,997
Non-accrual with allowance	41,422	24,896
Popular U.S. | Construction
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance		0
Non-accrual with allowance		0
Popular U.S. | Mortgages
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	190	120
Non-accrual with allowance	27,881	11,071
Popular U.S. | Commercial | Commercial multi-family
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	8,700	0
Non-accrual with allowance	0	0
Popular U.S. | Commercial | CRE non-owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	1,344	0
Non-accrual with allowance	1,063	1,117
Popular U.S. | Commercial | CRE owner occupied
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	3,877	3,877
Non-accrual with allowance	0	2,397
Popular U.S. | Commercial | Commercial and Industrial
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	6,423	3,772
Popular U.S. | Leasing
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	0	0
Popular U.S. | Consumer | Home equity lines of credit
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	3,986	3,733
Popular U.S. | Consumer | Personal loans
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	2,068	2,805
Popular U.S. | Consumer | Auto Loan
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	0	0
Popular U.S. | Consumer | Other
Financing receivable nonaccrual status [Line Items]
Non-accrual with no allowance	0	0
Non-accrual with allowance	$ 1	$ 1