Loans - Loans held-in-portfolio in past due status, non-performing status and accruing loans past-due 90 days or more by loan class (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment, Past Due
Past Due	$ 1,690,762	$ 2,269,553
Current	27,371,855	27,115,643
Loans held in portfolio, net of unearned income	29,062,617	29,385,196
Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	270,589	361,661
Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	101,675	142,054
Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	1,318,498	1,765,838
Non-accrual loans	685,183	737,774
Accruing loans past-due 90 days or more	633,315	1,028,064
Construction
Financing Receivable, Recorded Investment, Past Due
Past Due	17,957	50,369
Current	847,156	875,839
Loans held in portfolio, net of unearned income	865,113	926,208
Construction \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	21,312
Construction \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	3,080	0
Construction \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	14,877	29,057
Non-accrual loans	14,877	29,057
Accruing loans past-due 90 days or more	0	0
Mortgages
Financing Receivable, Recorded Investment, Past Due
Past Due	1,254,272	1,775,902
Current	6,424,206	6,114,778
Loans held in portfolio, net of unearned income	7,678,478	7,890,680
Mortgages \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	167,277	229,024
Mortgages \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	78,497	103,190
Mortgages \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	1,008,498	1,443,688
Non-accrual loans	383,976	429,207
Accruing loans past-due 90 days or more	624,522	1,014,481
Commercial \| Commercial multi-family
Financing Receivable, Recorded Investment, Past Due
Past Due	6,474	8,468
Current	1,884,362	1,887,523
Loans held in portfolio, net of unearned income	1,890,836	1,895,991
Commercial \| Commercial multi-family \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	128	6,069
Commercial \| Commercial multi-family \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	0
Commercial \| Commercial multi-family \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	6,346	2,399
Non-accrual loans	6,346	2,399
Accruing loans past-due 90 days or more	0	0
Commercial \| CRE non-owner occupied
Financing Receivable, Recorded Investment, Past Due
Past Due	105,501	88,062
Current	4,020,162	3,913,081
Loans held in portfolio, net of unearned income	4,125,663	4,001,143
Commercial \| CRE non-owner occupied \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	32,749	3,113
Commercial \| CRE non-owner occupied \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	7,143
Commercial \| CRE non-owner occupied \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	72,752	77,806
Non-accrual loans	72,752	77,806
Accruing loans past-due 90 days or more	0	0
Commercial \| CRE owner occupied
Financing Receivable, Recorded Investment, Past Due
Past Due	86,146	102,664
Current	1,718,467	1,840,611
Loans held in portfolio, net of unearned income	1,804,613	1,943,275
Commercial \| CRE owner occupied \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	4,902	8,461
Commercial \| CRE owner occupied \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	1,243	1,868
Commercial \| CRE owner occupied \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	80,001	92,335
Non-accrual loans	80,001	92,335
Accruing loans past-due 90 days or more	0	0
Commercial \| Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due
Past Due	73,648	50,290
Current	5,543,172	5,723,611
Loans held in portfolio, net of unearned income	5,616,820	5,773,901
Commercial \| Commercial and Industrial \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	5,384	11,340
Commercial \| Commercial and Industrial \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	1,191	847
Commercial \| Commercial and Industrial \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	67,073	38,103
Non-accrual loans	66,466	37,540
Accruing loans past-due 90 days or more	607	563
Leasing
Financing Receivable, Recorded Investment, Past Due
Past Due	10,443	14,009
Current	1,287,485	1,183,652
Loans held in portfolio, net of unearned income	1,297,928	1,197,661
Leasing \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	6,054	9,141
Leasing \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	2,103	1,427
Leasing \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	2,286	3,441
Non-accrual loans	2,286	3,441
Accruing loans past-due 90 days or more	0	0
Consumer \| Credit card
Financing Receivable, Recorded Investment, Past Due
Past Due	15,218	23,970
Current	864,943	895,996
Loans held in portfolio, net of unearned income	880,161	919,966
Consumer \| Credit card \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	4,371	6,550
Consumer \| Credit card \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	2,826	4,619
Consumer \| Credit card \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	8,021	12,801
Non-accrual loans	0	0
Accruing loans past-due 90 days or more	8,021	12,801
Consumer \| Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due
Past Due	7,088	8,301
Current	78,339	90,449
Loans held in portfolio, net of unearned income	85,427	98,750
Consumer \| Home equity lines of credit \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	501	420
Consumer \| Home equity lines of credit \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	210	342
Consumer \| Home equity lines of credit \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	6,377	7,539
Non-accrual loans	6,377	7,491
Accruing loans past-due 90 days or more	0	48
Consumer \| Personal loans
Financing Receivable, Recorded Investment, Past Due
Past Due	39,693	50,041
Current	1,362,596	1,426,944
Loans held in portfolio, net of unearned income	1,402,289	1,476,985
Consumer \| Personal loans \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	9,977	12,741
Consumer \| Personal loans \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	5,023	9,439
Consumer \| Personal loans \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	24,693	27,861
Non-accrual loans	24,693	27,861
Accruing loans past-due 90 days or more	0	0
Consumer \| Auto Loan
Financing Receivable, Recorded Investment, Past Due
Past Due	59,723	81,618
Current	3,229,304	3,050,610
Loans held in portfolio, net of unearned income	3,289,027	3,132,228
Consumer \| Auto Loan \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	39,032	53,186
Consumer \| Auto Loan \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	7,405	12,696
Consumer \| Auto Loan \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	13,286	15,736
Non-accrual loans	13,286	15,736
Accruing loans past-due 90 days or more	0	0
Consumer \| Other
Financing Receivable, Recorded Investment, Past Due
Past Due	14,599	15,859
Current	111,663	112,549
Loans held in portfolio, net of unearned income	126,262	128,408
Consumer \| Other \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	214	304
Consumer \| Other \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	97	483
Consumer \| Other \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	14,288	15,072
Non-accrual loans	14,123	14,901
Accruing loans past-due 90 days or more	165	171
Puerto Rico
Financing Receivable, Recorded Investment, Past Due
Past Due	1,647,878	2,146,682
Current	19,500,157	19,426,598
Loans held in portfolio, net of unearned income	21,148,035	21,573,280
Puerto Rico \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	263,041	297,700
Puerto Rico \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	94,733	120,544
Puerto Rico \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	1,290,104	1,728,438
Non-accrual loans	656,789	700,377
Accruing loans past-due 90 days or more	633,315	1,028,061
Puerto Rico \| Construction
Financing Receivable, Recorded Investment, Past Due
Past Due	17,957	21,497
Current	124,990	135,609
Loans held in portfolio, net of unearned income	142,947	157,106
Puerto Rico \| Construction \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	0
Puerto Rico \| Construction \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	3,080	0
Puerto Rico \| Construction \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	14,877	21,497
Non-accrual loans	14,877	21,497
Accruing loans past-due 90 days or more	0	0
Puerto Rico \| Mortgages
Financing Receivable, Recorded Investment, Past Due
Past Due	1,233,446	1,712,152
Current	5,281,711	5,057,991
Loans held in portfolio, net of unearned income	6,515,157	6,770,143
Puerto Rico \| Mortgages \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	164,779	195,602
Puerto Rico \| Mortgages \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	73,492	87,726
Puerto Rico \| Mortgages \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	995,175	1,428,824
Non-accrual loans	370,653	414,343
Accruing loans past-due 90 days or more	624,522	1,014,481
Puerto Rico \| Commercial \| Commercial multi-family
Financing Receivable, Recorded Investment, Past Due
Past Due	525	1,301
Current	151,258	150,979
Loans held in portfolio, net of unearned income	151,783	152,280
Puerto Rico \| Commercial \| Commercial multi-family \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	128	796
Puerto Rico \| Commercial \| Commercial multi-family \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	0
Puerto Rico \| Commercial \| Commercial multi-family \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	397	505
Non-accrual loans	397	505
Accruing loans past-due 90 days or more	0	0
Puerto Rico \| Commercial \| CRE non-owner occupied
Financing Receivable, Recorded Investment, Past Due
Past Due	105,127	82,829
Current	1,888,302	1,924,504
Loans held in portfolio, net of unearned income	1,993,429	2,007,333
Puerto Rico \| Commercial \| CRE non-owner occupied \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	32,749	2,189
Puerto Rico \| Commercial \| CRE non-owner occupied \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	3,503
Puerto Rico \| Commercial \| CRE non-owner occupied \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	72,378	77,137
Non-accrual loans	72,378	77,137
Accruing loans past-due 90 days or more	0	0
Puerto Rico \| Commercial \| CRE owner occupied
Financing Receivable, Recorded Investment, Past Due
Past Due	84,407	101,489
Current	1,380,022	1,497,406
Loans held in portfolio, net of unearned income	1,464,429	1,598,895
Puerto Rico \| Commercial \| CRE owner occupied \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	3,995	8,270
Puerto Rico \| Commercial \| CRE owner occupied \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	604	1,218
Puerto Rico \| Commercial \| CRE owner occupied \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	79,808	92,001
Non-accrual loans	79,808	92,001
Accruing loans past-due 90 days or more	0	0
Puerto Rico \| Commercial \| Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due
Past Due	68,723	46,010
Current	3,952,675	4,183,098
Loans held in portfolio, net of unearned income	4,021,398	4,229,108
Puerto Rico \| Commercial \| Commercial and Industrial \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	2,314	10,223
Puerto Rico \| Commercial \| Commercial and Industrial \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	682	775
Puerto Rico \| Commercial \| Commercial and Industrial \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	65,727	35,012
Non-accrual loans	65,120	34,449
Accruing loans past-due 90 days or more	607	563
Puerto Rico \| Leasing
Financing Receivable, Recorded Investment, Past Due
Past Due	10,443	14,009
Current	1,287,485	1,183,652
Loans held in portfolio, net of unearned income	1,297,928	1,197,661
Puerto Rico \| Leasing \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	6,054	9,141
Puerto Rico \| Leasing \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	2,103	1,427
Puerto Rico \| Leasing \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	2,286	3,441
Non-accrual loans	2,286	3,441
Accruing loans past-due 90 days or more	0	0
Puerto Rico \| Consumer \| Credit card
Financing Receivable, Recorded Investment, Past Due
Past Due	15,218	23,967
Current	864,912	895,968
Loans held in portfolio, net of unearned income	880,130	919,935
Puerto Rico \| Consumer \| Credit card \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	4,371	6,550
Puerto Rico \| Consumer \| Credit card \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	2,826	4,619
Puerto Rico \| Consumer \| Credit card \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	8,021	12,798
Non-accrual loans	0	0
Accruing loans past-due 90 days or more	8,021	12,798
Puerto Rico \| Consumer \| Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due
Past Due	0	232
Current	3,489	3,947
Loans held in portfolio, net of unearned income	3,489	4,179
Puerto Rico \| Consumer \| Home equity lines of credit \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	184
Puerto Rico \| Consumer \| Home equity lines of credit \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	0
Puerto Rico \| Consumer \| Home equity lines of credit \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	0	48
Non-accrual loans	0	0
Accruing loans past-due 90 days or more	0	48
Puerto Rico \| Consumer \| Personal loans
Financing Receivable, Recorded Investment, Past Due
Past Due	37,710	45,739
Current	1,227,582	1,232,008
Loans held in portfolio, net of unearned income	1,265,292	1,277,747
Puerto Rico \| Consumer \| Personal loans \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	9,405	11,255
Puerto Rico \| Consumer \| Personal loans \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	4,444	8,097
Puerto Rico \| Consumer \| Personal loans \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	23,861	26,387
Non-accrual loans	23,861	26,387
Accruing loans past-due 90 days or more	0	0
Puerto Rico \| Consumer \| Auto Loan
Financing Receivable, Recorded Investment, Past Due
Past Due	59,723	81,618
Current	3,229,304	3,050,610
Loans held in portfolio, net of unearned income	3,289,027	3,132,228
Puerto Rico \| Consumer \| Auto Loan \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	39,032	53,186
Puerto Rico \| Consumer \| Auto Loan \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	7,405	12,696
Puerto Rico \| Consumer \| Auto Loan \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	13,286	15,736
Non-accrual loans	13,286	15,736
Accruing loans past-due 90 days or more	0	0
Puerto Rico \| Consumer \| Other
Financing Receivable, Recorded Investment, Past Due
Past Due	14,599	15,839
Current	108,427	110,826
Loans held in portfolio, net of unearned income	123,026	126,665
Puerto Rico \| Consumer \| Other \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	214	304
Puerto Rico \| Consumer \| Other \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	97	483
Puerto Rico \| Consumer \| Other \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	14,288	15,052
Non-accrual loans	14,123	14,881
Accruing loans past-due 90 days or more	165	171
Popular U.S.
Financing Receivable, Recorded Investment, Past Due
Past Due	42,884	122,871
Current	7,871,698	7,689,045
Loans held in portfolio, net of unearned income	7,914,582	7,811,916
Popular U.S. \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	7,548	63,961
Popular U.S. \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	6,942	21,510
Popular U.S. \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	28,394	37,400
Non-accrual loans	28,394	37,397
Accruing loans past-due 90 days or more	0	3
Popular U.S. \| Construction
Financing Receivable, Recorded Investment, Past Due
Past Due	0	28,872
Current	722,166	740,230
Loans held in portfolio, net of unearned income	722,166	769,102
Popular U.S. \| Construction \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	21,312
Popular U.S. \| Construction \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	0
Popular U.S. \| Construction \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	0	7,560
Non-accrual loans	0	7,560
Accruing loans past-due 90 days or more	0	0
Popular U.S. \| Mortgages
Financing Receivable, Recorded Investment, Past Due
Past Due	20,826	63,750
Current	1,142,495	1,056,787
Loans held in portfolio, net of unearned income	1,163,321	1,120,537
Popular U.S. \| Mortgages \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	2,498	33,422
Popular U.S. \| Mortgages \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	5,005	15,464
Popular U.S. \| Mortgages \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	13,323	14,864
Non-accrual loans	13,323	14,864
Accruing loans past-due 90 days or more	0	0
Popular U.S. \| Commercial \| Commercial multi-family
Financing Receivable, Recorded Investment, Past Due
Past Due	5,949	7,167
Current	1,733,104	1,736,544
Loans held in portfolio, net of unearned income	1,739,053	1,743,711
Popular U.S. \| Commercial \| Commercial multi-family \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	5,273
Popular U.S. \| Commercial \| Commercial multi-family \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	0
Popular U.S. \| Commercial \| Commercial multi-family \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	5,949	1,894
Non-accrual loans	5,949	1,894
Accruing loans past-due 90 days or more	0	0
Popular U.S. \| Commercial \| CRE non-owner occupied
Financing Receivable, Recorded Investment, Past Due
Past Due	374	5,233
Current	2,131,860	1,988,577
Loans held in portfolio, net of unearned income	2,132,234	1,993,810
Popular U.S. \| Commercial \| CRE non-owner occupied \| Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	924
Popular U.S. \| Commercial \| CRE non-owner occupied \| Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due
Past Due	0	3,640
Popular U.S. \| Commercial \| CRE non-owner occupied \| Past due 90 days or more
Financing Receivable, Recorded Investment, Past Due
Past Due	374	669
Non-accrual loans	374	669
Accruing loans past-due 90 days or more	0	0
Popular U.S. \| Commercial \| CRE owner occupied
Financing Receivable, Recorded Investment, Past Due
Past Due	1,739	1,175
Current	338,445	343,205
Loans held in portfolio, net of unearned income	340,184	344,380

Loans - Loans held-in-portfolio in past due status, non-performing status and accruing loans past-due 90 days or more by loan class (Details) - USD ($)
$ in Thousands